AMDGPU: Mark all unspecified CC functions in tests as amdgpu_kernel

Currently the default C calling convention functions are treated
the same as compute kernels. Make this explicit so the default
calling convention can be changed to a non-kernel.

Converted with perl -pi -e 's/define void/define amdgpu_kernel void/'
on the relevant test directories (and undoing in one place that actually
wanted a non-kernel).

llvm-svn: 298444
diff --git a/llvm/test/CodeGen/AMDGPU/opencl-image-metadata.ll b/llvm/test/CodeGen/AMDGPU/opencl-image-metadata.ll
index 0242f6d..c974471 100644
--- a/llvm/test/CodeGen/AMDGPU/opencl-image-metadata.ll
+++ b/llvm/test/CodeGen/AMDGPU/opencl-image-metadata.ll
@@ -6,7 +6,7 @@
 
 ; EG: CF_END
 ; SI: s_endpgm
-define void @kernel(i32 addrspace(1)* %out) {
+define amdgpu_kernel void @kernel(i32 addrspace(1)* %out) {
 entry:
   store i32 0, i32 addrspace(1)* %out
   ret void