[Sanitizers][ABI] Remove too strong assert in asan_abi_shim (llvm#81696)

Recently we enabled building the shim for arm64_32 arch. On this arch,
sizeof(uptr) == sizeof(unsigned long) == 4 - so this assert will fail in
runtime.

Need to just remove this assert

rdar://122927166

Co-authored-by: Mariusz Borsa <[email protected]>

Author: wrotki

compiler-rt/lib/asan_abi/asan_abi_shim.cpp

@@ -54,7 +54,7 @@ void *__asan_memmove(void *dest, const void *src, uptr n) {
 
 // Functions concerning RTL startup and initialization
 void __asan_init(void) {
-  static_assert(sizeof(uptr) == 8);
+  static_assert(sizeof(uptr) == 8 || sizeof(uptr) == 4);
   static_assert(sizeof(u64) == 8);
   static_assert(sizeof(u32) == 4);