Canonicalize header guards into a common format.

Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)

Changes made by clang-tidy with minor tweaks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215558 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/R600/AMDGPUTargetMachine.h

@@ -12,8 +12,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef AMDGPU_TARGET_MACHINE_H
-#define AMDGPU_TARGET_MACHINE_H
+#ifndef LLVM_LIB_TARGET_R600_AMDGPUTARGETMACHINE_H
+#define LLVM_LIB_TARGET_R600_AMDGPUTARGETMACHINE_H
 
 #include "AMDGPUFrameLowering.h"
 #include "AMDGPUInstrInfo.h"
@@ -45,4 +45,4 @@ public:
 
 } // End namespace llvm
 
-#endif // AMDGPU_TARGET_MACHINE_H
+#endif