AMDGPU: Add instruction definitions for some scratch_* instructions

Omit atomics for now since they probably aren't useful.

llvm-svn: 308747
diff --git a/llvm/lib/Target/AMDGPU/AMDGPU.td b/llvm/lib/Target/AMDGPU/AMDGPU.td
index 79d47f5..e70d056 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPU.td
+++ b/llvm/lib/Target/AMDGPU/AMDGPU.td
@@ -687,6 +687,8 @@
 
 def HasFlatGlobalInsts : Predicate<"Subtarget->hasFlatGlobalInsts()">,
   AssemblerPredicate<"FeatureFlatGlobalInsts">;
+def HasFlatScratchInsts : Predicate<"Subtarget->hasFlatScratchInsts()">,
+  AssemblerPredicate<"FeatureFlatScratchInsts">;
 
 def HasAddNoCarryInsts : Predicate<"Subtarget->hasAddNoCarryInsts()">,
   AssemblerPredicate<"FeatureAddNoCarryInsts">;