Revert "TargetMachine: Merge TargetMachine and LLVMTargetMachine"

Reverting to investigate layering effects of MCJIT not linking
libCodeGen but using TargetMachine::getNameWithPrefix() breaking the
lldb bots.

This reverts commit r315633.

llvm-svn: 315637
diff --git a/llvm/lib/Target/Sparc/SparcTargetMachine.h b/llvm/lib/Target/Sparc/SparcTargetMachine.h
index 69f8ba7..b0d76ab 100644
--- a/llvm/lib/Target/Sparc/SparcTargetMachine.h
+++ b/llvm/lib/Target/Sparc/SparcTargetMachine.h
@@ -20,7 +20,7 @@
 
 namespace llvm {
 
-class SparcTargetMachine : public TargetMachine {
+class SparcTargetMachine : public LLVMTargetMachine {
   std::unique_ptr<TargetLoweringObjectFile> TLOF;
   SparcSubtarget Subtarget;
   bool is64Bit;