[clang] [clang][HIP] Normalize __cdecl on abstract function types to the device default CC on amdgcnspirv (PR #210882)

[Arseniy Obolenskiy via cfe-commits]

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@@ -1,11 +1,12 @@
 // RUN: %clang_cc1 -isystem %S/Inputs/ -fsycl-is-device -triple spirv64 -aux-triple x86_64-pc-windows-msvc -fsyntax-only -verify %s
 // RUN: %clang_cc1 -isystem %S/Inputs/ -fsycl-is-device -triple spirv64 -fsyntax-only -verify=expected,no-aux %s
 
-// Check that there is no error/warning emitted for cdecl functions compiled for
-// SYCL device. Make sure variadic calls from within device code are diagnosed.
+// Check that there is no error/warning emitted for non-variadic cdecl functions
+// compiled for SYCL device. Make sure variadic cdecl functions and variadic
+// calls from within device code are diagnosed.
 
 // no-aux-warning at +2 {{'__cdecl' calling convention is not supported for this target}}
-// no-aux-error at +1 {{variadic function cannot use spir_function calling convention}}
+// expected-error at +1 {{variadic function cannot use cdecl calling convention}}
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aobolensk wrote:

It would have been, but the error is gone for both now

https://github.com/llvm/llvm-project/pull/210882