TargetMachine: Merge TargetMachine and LLVMTargetMachine

Merge LLVMTargetMachine into TargetMachine.

- There is no in-tree target anymore that just implements TargetMachine
  but not LLVMTargetMachine.
- It should still be possible to stub out all the various functions in
  case a target does not want to use lib/CodeGen
- This simplifies the code and avoids methods ending up in the wrong
  interface.

Differential Revision: https://reviews.llvm.org/D38489

llvm-svn: 315633
diff --git a/llvm/unittests/CodeGen/MachineInstrTest.cpp b/llvm/unittests/CodeGen/MachineInstrTest.cpp
index 89041e2..bd61bf0 100644
--- a/llvm/unittests/CodeGen/MachineInstrTest.cpp
+++ b/llvm/unittests/CodeGen/MachineInstrTest.cpp
@@ -62,11 +62,11 @@
   TargetInstrInfo TII;
 };
 
-class BogusTargetMachine : public LLVMTargetMachine {
+class BogusTargetMachine : public TargetMachine {
 public:
   BogusTargetMachine()
-      : LLVMTargetMachine(Target(), "", Triple(""), "", "", TargetOptions(),
-                          Reloc::Static, CodeModel::Small, CodeGenOpt::Default),
+      : TargetMachine(Target(), "", Triple(""), "", "", TargetOptions(),
+                      Reloc::Static, CodeModel::Small, CodeGenOpt::Default),
         ST(*this) {}
   ~BogusTargetMachine() override {}