modules: Move ProfileKinds to an anonymous namespace

Fix a build failure with `LLVM_ENABLE_MODULES` due to
`ProfileData::instr` conflicting with a function `instr()` in
`<curses.h>`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239793 91177308-0d34-0410-b5e6-96231b3b80d8

tools/llvm-profdata/llvm-profdata.cpp

@@ -37,7 +37,9 @@ static void exitWithError(const Twine &Message, StringRef Whence = "") {
   ::exit(1);
 }
 
+namespace {
 enum ProfileKinds { instr, sample };
+}
 
 static void mergeInstrProfile(const cl::list<std::string> &Inputs,
                               StringRef OutputFilename) {