Rollup merge of rust-lang#35141 - eddyb:assert-mir-debug, r=nagisa

rustc_trans: apply the debug location for the MIR Assert panic call.

Helps `libcore` build with MIR trans and debuginfo; libcore has the body of `panic`, which resulted in:
```
inlinable function call in a function with debug info must have a !dbg location
  call void @_ZN4core9panicking5panic17h585bd70cda921012E({ %str_slice, %str_slice, i32 }* @panic_loc12745)
LLVM ERROR: Broken function found, compilation aborted!
```

src/librustc_trans/mir/block.rs

@@ -284,6 +284,7 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
 
                 // After this point, bcx is the block for the call to panic.
                 bcx = panic_block.build();
+                debug_loc.apply_to_bcx(&bcx);
 
                 // Get the location information.
                 let loc = bcx.sess().codemap().lookup_char_pos(span.lo);