Add ifdef around getSubtargetFeatureName in tablegen output file so that only targets that want the function get it. This prevents other targets from getting an unused function warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155538 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/AsmMatcherEmitter.cpp b/utils/TableGen/AsmMatcherEmitter.cpp
index 03807b1..8375168 100644
--- a/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/utils/TableGen/AsmMatcherEmitter.cpp
@@ -2395,13 +2395,17 @@
 
   OS << "#endif // GET_REGISTER_MATCHER\n\n";
 
-
-  OS << "\n#ifdef GET_MATCHER_IMPLEMENTATION\n";
-  OS << "#undef GET_MATCHER_IMPLEMENTATION\n\n";
+  OS << "\n#ifdef GET_SUBTARGET_FEATURE_NAME\n";
+  OS << "#undef GET_SUBTARGET_FEATURE_NAME\n\n";
 
   // Generate the helper function to get the names for subtarget features.
   emitGetSubtargetFeatureName(Info, OS);
 
+  OS << "#endif // GET_SUBTARGET_FEATURE_NAME\n\n";
+
+  OS << "\n#ifdef GET_MATCHER_IMPLEMENTATION\n";
+  OS << "#undef GET_MATCHER_IMPLEMENTATION\n\n";
+
   // Generate the function that remaps for mnemonic aliases.
   bool HasMnemonicAliases = emitMnemonicAliases(OS, Info);