move getNameWithPrefix and getSymbol to TargetMachine.

TargetLoweringBase is implemented in CodeGen, so before this patch we had
a dependency fom Target to CodeGen. This would show up as a link failure of
llvm-stress when building with -DBUILD_SHARED_LIBS=ON.

This fixes pr18900.

llvm-svn: 201711
diff --git a/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp b/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
index cc40361..029bb8a 100644
--- a/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
+++ b/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
@@ -57,7 +57,7 @@
     Mang->getNameWithPrefix(Name, MO.getSymbolName());
   } else {
     const GlobalValue *GV = MO.getGlobal();
-    TM.getTargetLowering()->getNameWithPrefix(Name, GV, *Mang);
+    TM.getNameWithPrefix(Name, GV, *Mang);
   }
 
   unsigned OrigLen = Name.size() - PrefixLen;