[clang] [Clang][AArch64] Remove unwarranted 'cannot be used in non-streaming mode' diagnostic. (PR #150592)

[Sander de Smalen via cfe-commits]

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@@ -5988,11 +5988,9 @@ bool clang::IsArmStreamingFunction(const FunctionDecl *FD,
     if (FD->hasAttr<ArmLocallyStreamingAttr>())
       return true;
 
-  if (const Type *Ty = FD->getType().getTypePtrOrNull())
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sdesmalen-arm wrote:

When I said "the type is null", I meant that the QualType is `QualType()` <=> `QualType::isNull() == true`. With asserts enabled the `operator->` that returns the `Type*` has an explicit assert that the type is not `QualType()`:
https://github.com/llvm/llvm-project/blob/main/clang/include/clang/AST/Type.h#L952
I'm happy to add an explicit assert in this function and to commit this as a separate change though.

https://github.com/llvm/llvm-project/pull/150592