[Arm64/Windows] Backport #9500 changes

src/vm/arm64/asmhelpers.asm

@@ -159,6 +159,7 @@
         RestoreRegMS 26, X26
         RestoreRegMS 27, X27
         RestoreRegMS 28, X28
+        RestoreRegMS 29, X29
 
 Done
         ; Its imperative that the return value of HelperMethodFrameRestoreState is zero
@@ -991,34 +992,49 @@ UM2MThunk_WrapperHelper_RegArgumentsSetup
 
         ; This helper enables us to call into a funclet after restoring Fp register
         NESTED_ENTRY CallEHFunclet
-
-        ; Using below prolog instead of PROLOG_SAVE_REG_PAIR fp,lr, #-16!
-        ; is intentional. Above statement would also emit instruction to save
-        ; sp in fp. If sp is saved in fp in prolog then it is not expected that fp can change in the body
-        ; of method. However, this method needs to be able to change fp before calling funclet.
-        ; This is required to access locals in funclet.
-        PROLOG_SAVE_REG_PAIR x19,x20, #-16!
-        PROLOG_SAVE_REG   fp, #0
-        PROLOG_SAVE_REG   lr, #8
-
         ; On entry:
         ;
         ; X0 = throwable        
         ; X1 = PC to invoke
         ; X2 = address of X19 register in CONTEXT record; used to restore the non-volatile registers of CrawlFrame
         ; X3 = address of the location where the SP of funclet's caller (i.e. this helper) should be saved.
         ;
+
+        ; Using below prolog instead of PROLOG_SAVE_REG_PAIR fp,lr, #-16!
+        ; is intentional. Above statement would also emit instruction to save
+        ; sp in fp. If sp is saved in fp in prolog then it is not expected that fp can change in the body
+        ; of method. However, this method needs to be able to change fp before calling funclet.
+        ; This is required to access locals in funclet.
+        PROLOG_SAVE_REG_PAIR_NO_FP fp,lr, #-96!
+
+        ; Spill callee saved registers
+        PROLOG_SAVE_REG_PAIR   x19, x20, 16
+        PROLOG_SAVE_REG_PAIR   x21, x22, 32
+        PROLOG_SAVE_REG_PAIR   x23, x24, 48
+        PROLOG_SAVE_REG_PAIR   x25, x26, 64
+        PROLOG_SAVE_REG_PAIR   x27, x28, 80
+
         ; Save the SP of this function. We cannot store SP directly.
         mov fp, sp
         str fp, [x3]
 
+        ldp x19, x20, [x2, #0]
+        ldp x21, x22, [x2, #16]
+        ldp x23, x24, [x2, #32]
+        ldp x25, x26, [x2, #48]
+        ldp x27, x28, [x2, #64]
         ldr fp, [x2, #80] ; offset of fp in CONTEXT relative to X19
 
         ; Invoke the funclet
         blr x1
         nop
 
-        EPILOG_RESTORE_REG_PAIR   fp, lr, #16!
+        EPILOG_RESTORE_REG_PAIR   x19, x20, 16
+        EPILOG_RESTORE_REG_PAIR   x21, x22, 32
+        EPILOG_RESTORE_REG_PAIR   x23, x24, 48
+        EPILOG_RESTORE_REG_PAIR   x25, x26, 64
+        EPILOG_RESTORE_REG_PAIR   x27, x28, 80
+        EPILOG_RESTORE_REG_PAIR   fp, lr, #96!
         EPILOG_RETURN
 
         NESTED_END CallEHFunclet