[Sanitizers] Modified __aarch64__ to use the 64 bit version of the allocator.

This change will switch SizeClassAllocator32 to SizeClassAllocator64 on ARM. This might potentially affect ARM platforms with 39-bit address space. This addresses [[ google/sanitizers#703  | issues/703  ]], but unlike [[ https://reviews.llvm.org/D60243 | D60243 ]] it defaults to 64 bit allocator.

Reviewed By: vitalybuka, MaskRay

Differential Revision: https://reviews.llvm.org/D137136

Author: kstoimenov

compiler-rt/lib/sanitizer_common/sanitizer_platform.h

@@ -286,8 +286,8 @@
 #ifndef SANITIZER_CAN_USE_ALLOCATOR64
 #  if (SANITIZER_ANDROID && defined(__aarch64__)) || SANITIZER_FUCHSIA
 #    define SANITIZER_CAN_USE_ALLOCATOR64 1
-#  elif defined(__mips64) || defined(__aarch64__) || defined(__i386__) || \
-      defined(__arm__) || SANITIZER_RISCV64 || defined(__hexagon__)
+#  elif defined(__mips64) || defined(__arm__) || defined(__i386__) || \
+      SANITIZER_RISCV64 || defined(__hexagon__)
 #    define SANITIZER_CAN_USE_ALLOCATOR64 0
 #  else
 #    define SANITIZER_CAN_USE_ALLOCATOR64 (SANITIZER_WORDSIZE == 64)