ac: use new LLVM 8 intrinsic when storing 16-bit values

vindex is always 0.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

src/amd/common/ac_llvm_build.h

@@ -343,6 +343,15 @@ ac_build_raw_tbuffer_load(struct ac_llvm_context *ctx,
 			  bool slc,
 		          bool can_speculate);
 
+void
+ac_build_tbuffer_store_short(struct ac_llvm_context *ctx,
+			     LLVMValueRef rsrc,
+			     LLVMValueRef vdata,
+			     LLVMValueRef voffset,
+			     LLVMValueRef soffset,
+			     bool glc,
+			     bool writeonly_memory);
+
 void
 ac_build_struct_tbuffer_store(struct ac_llvm_context *ctx,
 			      LLVMValueRef rsrc,