Remove unneeded printString methods

[Jaysonyan]

Summary

As mentioned in D114223#inline-1095135 both std::string and char * implicitly convert to StringRef so these overloaded methods are not needed.

[jhenderson]

LGTM, assuming nothing fell over in a local build.

llvm/include/llvm/Support/ScopedPrinter.h

public:
   }
 
   virtual void printString(StringRef Value) { startLine() << Value << "\n"; }
 
   virtual void printString(StringRef Label, StringRef Value) {
     startLine() << Label << ": " << Value << "\n";
   }
 
-  void printString(StringRef Label, const std::string &Value) {
-    printString(Label, StringRef(Value));
-  }
-
-  void printString(StringRef Label, const char *Value) {
-    printString(Label, StringRef(Value));
-  }
-
   template <typename T>
   void printNumber(StringRef Label, StringRef Str, T Value) {
     printNumberImpl(Label, Str, to_string(Value));
   }
 
   void printBinary(StringRef Label, StringRef Str, ArrayRef<uint8_t> Value) {
     printBinaryImpl(Label, Str, Value, false);
   }