Remove superfluous .str() and replace std::string concatenation with Twine.

llvm-svn: 233392
diff --git a/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp b/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
index 0965cb35..6df89fe 100644
--- a/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
+++ b/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
@@ -66,7 +66,7 @@
   unsigned OrigLen = Name.size() - PrefixLen;
 
   Name += Suffix;
-  MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name.str());
+  MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name);
   StringRef OrigName = StringRef(Name).substr(PrefixLen, OrigLen);
 
   // If the target flags on the operand changes the name of the symbol, do that