Replace hex number representation in ASM files

This commit fixes coreclr to build in newer versions of llvm (tested
with llvm 8 on Fedora 30).

These recent versions of llvm (as well as GCC) do not accept values like
"20h" as valid integer literals:

    src/debug/ee/amd64/dbghelpers.S:32:21: error: unknown token in expression
	    add rsp, 20h
			^

This was reported as a bug to llvm upstream and they explicitly rejected
supporting these literals: https://reviews.llvm.org/D59810

This is partial backport of cbd672e
(PR dotnet#22810), which was about adding compatiblity with GCC 5.

src/debug/ee/amd64/dbghelpers.S

@@ -29,7 +29,7 @@ NESTED_ENTRY FuncEvalHijack, _TEXT, UnhandledExceptionHandlerUnix
         //
         // epilogue
         //
-        add     rsp, 20h
+        add     rsp, 0x20
         TAILJMP_RAX
 NESTED_END FuncEvalHijack, _TEXT
 
@@ -55,7 +55,7 @@ NESTED_ENTRY ExceptionHijack, _TEXT, UnhandledExceptionHandlerUnix
         alloc_stack 0x20
         END_PROLOGUE
 
-        // We used to do an "alloc_stack 0h" because the stack has been allocated for us
+        // We used to do an "alloc_stack 0x0" because the stack has been allocated for us
         // by the OOP hijacking routine.  Our arguments have also been pushed onto the 
         // stack for us.  However, the Orcas compilers don't like a 0-sized frame, so 
         // we need to allocate something here and then just copy the stack arguments to 
@@ -65,14 +65,14 @@ NESTED_ENTRY ExceptionHijack, _TEXT, UnhandledExceptionHandlerUnix
         // its arguments on the stack. In x64, it gets its arguments in
         // registers (set up for us by DacDbiInterfaceImpl::Hijack),
         // and this stack space may be reused.
-        mov     rax, [rsp + 20h]
+        mov     rax, [rsp + 0x20]
         mov     [rsp], rax
-        mov     rax, [rsp + 28h]
-        mov     [rsp + 8h], rax
-        mov     rax, [rsp + 30h]
-        mov     [rsp + 10h], rax
-        mov     rax, [rsp + 38h]
-        mov     [rsp + 18h], rax
+        mov     rax, [rsp + 0x28]
+        mov     [rsp + 0x8], rax
+        mov     rax, [rsp + 0x30]
+        mov     [rsp + 0x10], rax
+        mov     rax, [rsp + 0x38]
+        mov     [rsp + 0x18], rax
 
         // DD Hijack primitive already set the stack. So just make the call now.
         call    C_FUNC(ExceptionHijackWorker)
@@ -93,7 +93,7 @@ NESTED_ENTRY ExceptionHijack, _TEXT, UnhandledExceptionHandlerUnix
         //
         // epilogue
         //
-        add     rsp, 20h
+        add     rsp, 0x20
         TAILJMP_RAX
 
 // Put a label here to tell the debugger where the end of this function is.

src/pal/inc/unixasmmacros.inc

@@ -2,7 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-#define INVALIDGCVALUE 0CCCCCCCDh
+#define INVALIDGCVALUE 0xCCCCCCCD
 
 #if defined(__APPLE__)
 #define C_FUNC(name) _##name

src/vm/amd64/jithelpers_fast.S

@@ -81,14 +81,14 @@ LEAF_ENTRY JIT_WriteBarrier, _TEXT
         // Update the write watch table if necessary
         mov     rax, rdi
         movabs  r10, 0xF0F0F0F0F0F0F0F0
-        shr     rax, 0Ch // SoftwareWriteWatch::AddressToTableByteIndexShift
+        shr     rax, 0xC // SoftwareWriteWatch::AddressToTableByteIndexShift
         NOP_2_BYTE // padding for alignment of constant
         movabs  r11, 0xF0F0F0F0F0F0F0F0
         add     rax, r10
-        cmp     byte ptr [rax], 0h
+        cmp     byte ptr [rax], 0x0
         .byte 0x75, 0x06
         // jne     CheckCardTable
-        mov     byte ptr [rax], 0FFh
+        mov     byte ptr [rax], 0xFF
 
         NOP_3_BYTE // padding for alignment of constant
 
@@ -112,27 +112,27 @@ LEAF_ENTRY JIT_WriteBarrier, _TEXT
 
         // Touch the card table entry, if not already dirty.
         shr     rdi, 0x0B
-        cmp     byte ptr [rdi + rax], 0FFh
+        cmp     byte ptr [rdi + rax], 0xFF
         .byte 0x75, 0x02
         // jne     UpdateCardTable
         REPRET
 
     UpdateCardTable:
-        mov     byte ptr [rdi + rax], 0FFh
+        mov     byte ptr [rdi + rax], 0xFF
 
 #ifdef FEATURE_MANUALLY_MANAGED_CARD_BUNDLES
         NOP_2_BYTE // padding for alignment of constant
         shr     rdi, 0x0A
 
         movabs  rax, 0xF0F0F0F0F0F0F0F0
-        cmp     byte ptr [rdi + rax], 0FFh
+        cmp     byte ptr [rdi + rax], 0xFF
 
         .byte 0x75, 0x02
         // jne     UpdateCardBundle_WriteWatch_PostGrow64
         REPRET
 
     UpdateCardBundle_WriteWatch_PostGrow64:
-        mov     byte ptr [rdi + rax], 0FFh
+        mov     byte ptr [rdi + rax], 0xFF
 #endif
 
         ret
@@ -312,15 +312,15 @@ LEAF_ENTRY JIT_ByRefWriteBarrier, _TEXT
 #ifdef FEATURE_USE_SOFTWARE_WRITE_WATCH_FOR_GC_HEAP
         // Update the write watch table if necessary
         PREPARE_EXTERNAL_VAR g_sw_ww_enabled_for_gc_heap, rax
-        cmp     byte ptr [rax], 0h
+        cmp     byte ptr [rax], 0x0
         je      CheckCardTable_ByRefWriteBarrier
         mov     rax, rdi
-        shr     rax, 0Ch // SoftwareWriteWatch::AddressToTableByteIndexShift
+        shr     rax, 0xC // SoftwareWriteWatch::AddressToTableByteIndexShift
         PREPARE_EXTERNAL_VAR g_sw_ww_table, r10
         add     rax, qword ptr [r10]
-        cmp     byte ptr [rax], 0h
+        cmp     byte ptr [rax], 0x0
         jne     CheckCardTable_ByRefWriteBarrier
-        mov     byte ptr [rax], 0FFh
+        mov     byte ptr [rax], 0xFF
 #endif
 
     CheckCardTable_ByRefWriteBarrier:
@@ -334,8 +334,8 @@ LEAF_ENTRY JIT_ByRefWriteBarrier, _TEXT
 
         // move current rdi value into rcx and then increment the pointers
         mov     rcx, rdi
-        add     rsi, 8h
-        add     rdi, 8h
+        add     rsi, 0x8
+        add     rdi, 0x8
 
         // Check if we need to update the card table
         // Calc pCardByte
@@ -345,13 +345,13 @@ LEAF_ENTRY JIT_ByRefWriteBarrier, _TEXT
         mov     rax, [rax]
 
         // Check if this card is dirty
-        cmp     byte ptr [rcx + rax], 0FFh
+        cmp     byte ptr [rcx + rax], 0xFF
 
         jne     UpdateCardTable_ByRefWriteBarrier
         REPRET
 
     UpdateCardTable_ByRefWriteBarrier:
-        mov     byte ptr [rcx + rax], 0FFh
+        mov     byte ptr [rcx + rax], 0xFF
 
 #ifdef FEATURE_MANUALLY_MANAGED_CARD_BUNDLES
         // Shift rcx by 0x0A more to get the card bundle byte (we shifted by 0x0B already)
@@ -361,13 +361,13 @@ LEAF_ENTRY JIT_ByRefWriteBarrier, _TEXT
         add     rcx, [rax]
 
         // Check if this bundle byte is dirty
-        cmp     byte ptr [rcx], 0FFh
+        cmp     byte ptr [rcx], 0xFF
 
         jne     UpdateCardBundle_ByRefWriteBarrier
         REPRET
 
     UpdateCardBundle_ByRefWriteBarrier:
-        mov     byte ptr [rcx], 0FFh
+        mov     byte ptr [rcx], 0xFF
 #endif
 
         ret
@@ -383,8 +383,8 @@ LEAF_ENTRY JIT_ByRefWriteBarrier, _TEXT
 #endif
     Exit_ByRefWriteBarrier:
         // Increment the pointers before leaving
-        add     rdi, 8h
-        add     rsi, 8h
+        add     rdi, 0x8
+        add     rsi, 0x8
         ret
 LEAF_END JIT_ByRefWriteBarrier, _TEXT