[scudo] GWP_ASAN runs on untagged pointers

It's already covered by multiple tests, but to trigger
this path we need MTE+GWP which disabled.

Reviewed By: hctim, pcc

Differential Revision: https://reviews.llvm.org/D105232

Author: vitalybuka

compiler-rt/lib/scudo/standalone/combined.h

@@ -569,9 +569,6 @@ class Allocator {
       reportAllocationSizeTooBig(NewSize, 0, MaxAllowedMallocSize);
     }
 
-    void *OldTaggedPtr = OldPtr;
-    OldPtr = getHeaderTaggedPointer(OldPtr);
-
     // The following cases are handled by the C wrappers.
     DCHECK_NE(OldPtr, nullptr);
     DCHECK_NE(NewSize, 0);
@@ -591,6 +588,9 @@ class Allocator {
     }
 #endif // GWP_ASAN_HOOKS
 
+    void *OldTaggedPtr = OldPtr;
+    OldPtr = getHeaderTaggedPointer(OldPtr);
+
     if (UNLIKELY(!isAligned(reinterpret_cast<uptr>(OldPtr), MinAlignment)))
       reportMisalignedPointer(AllocatorAction::Reallocating, OldPtr);