[tablegen] Use categories on options that only matter to one emitter.

Summary:
The categories are emitted in a strange order in this patch due to a bug in the
CommandLine library.

Reviewers: ab

Reviewed By: ab

Subscribers: ab, llvm-commits

Differential Revision: https://reviews.llvm.org/D30995

llvm-svn: 298843
diff --git a/llvm/utils/TableGen/TableGen.cpp b/llvm/utils/TableGen/TableGen.cpp
index aa1aefd..00d20f1 100644
--- a/llvm/utils/TableGen/TableGen.cpp
+++ b/llvm/utils/TableGen/TableGen.cpp
@@ -102,9 +102,10 @@
                     clEnumValN(GenRegisterBank, "gen-register-bank",
                                "Generate registers bank descriptions")));
 
+  cl::OptionCategory PrintEnumsCat("Options for -print-enums");
   cl::opt<std::string>
   Class("class", cl::desc("Print Enum list for this class"),
-          cl::value_desc("class name"));
+        cl::value_desc("class name"), cl::cat(PrintEnumsCat));
 
 bool LLVMTableGenMain(raw_ostream &OS, RecordKeeper &Records) {
   switch (Action) {