[clang] [Driver] Don't alias -mstrict-align to -mno-unaligned-access (PR #85350)

[Fangrui Song via cfe-commits]

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@@ -321,9 +321,11 @@ void aarch64::getAArch64TargetFeatures(const Driver &D,
     }
   }
 
-  if (Arg *A = Args.getLastArg(options::OPT_mno_unaligned_access,
-                               options::OPT_munaligned_access)) {
-    if (A->getOption().matches(options::OPT_mno_unaligned_access))
+  if (Arg *A = Args.getLastArg(
+          options::OPT_mstrict_align, options::OPT_mno_strict_align,
+          options::OPT_mno_unaligned_access, options::OPT_munaligned_access)) {
+    if (A->getOption().matches(options::OPT_mstrict_align) ||
+        A->getOption().matches(options::OPT_mno_unaligned_access))
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MaskRay wrote:

Thanks for the AArch64 notes. 
This HelpText (`AArch32 only`) change is to discourage `-munaligned-access` for AArch64, since GCC doesn't support `-munaligned-access`.

Personally I assume that most modern architectures should switch to `-mstrict-align`.

(Related, I have been trying to make more code compliant under `-fsanitize=alignment`, which might makes memory access operations with hardware check easier. 
)

https://github.com/llvm/llvm-project/pull/85350