[Clang][AArch64] Remove unwarranted 'cannot be used in non-streaming mode' diagnostic. (#150592)
Previously Clang would give an unwarranted error on the capture of '&a'
in the function below, even though the parent function and the lambda
are both `__arm_streaming` functions, when the target is compiled with
+sme only.
```
void test_both_streaming(int32_t *out) __arm_streaming {
svint32_t a;
[&a, &out]() __arm_streaming {
^
error: SVE vector type 'svint32_t' (aka '__SVInt32_t') cannot be used in a non-streaming function
a = svdup_s32(1);
svst1(svptrue_b32(), out, a);
}();
}
```
That seems to happen because when `checkTypeSupport` is called the
`FunctionDecl` context of the lambda isn't yet complete and
`FD->getType()` returns a Null `QualTy`.
This is loosely related to #94976 which removed a `FD->hasBody()` check
in the same place, because `hasBody()` may incorrectly return `false`
when Clang is still processing a function.
llvm-project
83d3770d - [Clang][AArch64] Remove unwarranted 'cannot be used in non-streaming mode' diagnostic. (#150592)
