Make TableGen mangle operand method names before putting in enum.

Make TableGen mangle operand method names before putting in enum.

The purpose of this patch is to allow PredicateMethods to be set to something
like "isUImm<8>", calling a C++ template method to reduce code duplication. For
this to work, the PredicateMethod must be mangled into a valid C++ identifier
for insertion into an enum.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172073 91177308-0d34-0410-b5e6-96231b3b80d8