Replace size method call of containers to empty method where appropriate

This patch was generated by a clang tidy checker that is being open sourced.
The documentation of that checker is the following:

/// The emptiness of a container should be checked using the empty method
/// instead of the size method. It is not guaranteed that size is a
/// constant-time function, and it is generally more efficient and also shows
/// clearer intent to use empty. Furthermore some containers may implement the
/// empty method but not implement the size method. Using empty whenever
/// possible makes it easier to switch to another container in the future.

Patch by Gábor Horváth!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226161 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/AsmMatcherEmitter.cpp

@@ -2653,7 +2653,7 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
      << " bool matchingInlineAsm,\n"
      << "                                unsigned VariantID = 0);\n";
 
-  if (Info.OperandMatchInfo.size()) {
+  if (!Info.OperandMatchInfo.empty()) {
     OS << "\n  enum OperandMatchResultTy {\n";
     OS << "    MatchOperand_Success,    // operand matched successfully\n";
     OS << "    MatchOperand_NoMatch,    // operand did not match\n";
@@ -3011,7 +3011,7 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
   OS << "  return Match_MissingFeature;\n";
   OS << "}\n\n";
 
-  if (Info.OperandMatchInfo.size())
+  if (!Info.OperandMatchInfo.empty())
     emitCustomOperandParsing(OS, Target, Info, ClassName, StringTable,
                              MaxMnemonicIndex);