[Basic] Use range-based for loops (NFC)

Author: kazutakahirata

clang/include/clang/Basic/PlistSupport.h

@@ -77,8 +77,7 @@ inline raw_ostream &EmitInteger(raw_ostream &o, int64_t value) {
 
 inline raw_ostream &EmitString(raw_ostream &o, StringRef s) {
   o << "<string>";
-  for (StringRef::const_iterator I = s.begin(), E = s.end(); I != E; ++I) {
-    char c = *I;
+  for (char c : s) {
     switch (c) {
     default:
       o << c;

clang/lib/Basic/Warnings.cpp

@@ -198,8 +198,7 @@ void clang::ProcessWarningOptions(DiagnosticsEngine &Diags,
       }
     }
 
-    for (unsigned i = 0, e = Opts.Remarks.size(); i != e; ++i) {
-      StringRef Opt = Opts.Remarks[i];
+    for (StringRef Opt : Opts.Remarks) {
       const auto Flavor = diag::Flavor::Remark;
 
       // Check to see if this warning starts with "no-", if so, this is a