[compiler-rt] [msan] Add 'MappingDesc::ALLOCATOR' type and check it is available (PR #85153)

[Vitaly Buka via llvm-commits]

================
@@ -236,7 +241,9 @@ inline bool addr_is_type(uptr addr, MappingDesc::Type mapping_type) {
   return false;
 }
 
-#define MEM_IS_APP(mem) addr_is_type((uptr)(mem), MappingDesc::APP)
+#define MEM_IS_APP(mem)                           \
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vitalybuka wrote:

```suggestion
#define MEM_IS_APP(mem) addr_is_type((uptr)(mem), MappingDesc::APP | MappingDesc::ALLOCATOR))
```

https://github.com/llvm/llvm-project/pull/85153