AMDGPU: Add a shader calling convention

This makes it possible to distinguish between mesa shaders
and other kernels even in the presence of compute shaders.

Patch By: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

Differential Revision: http://reviews.llvm.org/D18559

llvm-svn: 265589
diff --git a/llvm/test/CodeGen/AMDGPU/r600-encoding.ll b/llvm/test/CodeGen/AMDGPU/r600-encoding.ll
index 3a82ee3..99a7893 100644
--- a/llvm/test/CodeGen/AMDGPU/r600-encoding.ll
+++ b/llvm/test/CodeGen/AMDGPU/r600-encoding.ll
@@ -10,7 +10,7 @@
 ; R600: {{^}}test:
 ; R600: MUL_IEEE {{[ *TXYZWPVxyzw.,0-9]+}} ; encoding: [{{0x[0-9a-f]+,0x[0-9a-f]+,0x[0-9a-f]+,0x[0-9a-f]+,0x10,0x02,0x[0-9a-f]+,0x[0-9a-f]+}}]
 
-define void @test(<4 x float> inreg %reg0) #0 {
+define amdgpu_ps void @test(<4 x float> inreg %reg0) {
 entry:
   %r0 = extractelement <4 x float> %reg0, i32 0
   %r1 = extractelement <4 x float> %reg0, i32 1
@@ -21,5 +21,3 @@
 }
 
 declare void @llvm.R600.store.swizzle(<4 x float>, i32, i32)
-
-attributes #0 = { "ShaderType"="0" }