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/unittests/CodeGen/MachineInstrTest.cpp b/llvm/unittests/CodeGen/MachineInstrTest.cpp
index bd61bf0..89041e2 100644
--- a/llvm/unittests/CodeGen/MachineInstrTest.cpp
+++ b/llvm/unittests/CodeGen/MachineInstrTest.cpp
@@ -62,11 +62,11 @@
   TargetInstrInfo TII;
 };
 
-class BogusTargetMachine : public TargetMachine {
+class BogusTargetMachine : public LLVMTargetMachine {
 public:
   BogusTargetMachine()
-      : TargetMachine(Target(), "", Triple(""), "", "", TargetOptions(),
-                      Reloc::Static, CodeModel::Small, CodeGenOpt::Default),
+      : LLVMTargetMachine(Target(), "", Triple(""), "", "", TargetOptions(),
+                          Reloc::Static, CodeModel::Small, CodeGenOpt::Default),
         ST(*this) {}
   ~BogusTargetMachine() override {}