[compiler-rt] [compiler-rt][fuchsia] Preallocate a vmar for sanitizer internals (PR #75256)

[Roland McGrath via llvm-commits]

================
@@ -243,6 +290,12 @@ void UnmapOrDieVmar(void *addr, uptr size, zx_handle_t target_vmar) {
 
   zx_status_t status =
       _zx_vmar_unmap(target_vmar, reinterpret_cast<uintptr_t>(addr), size);
+  if (status != ZX_OK && target_vmar == gSanitizerHeapVmar) {
----------------
frobtech wrote:

Check for the specific error code returned for this case, which is `ZX_ERR_INVALID_ARGS`.


https://github.com/llvm/llvm-project/pull/75256