[Modules] Fix potential ODR violations by sinking the DEBUG_TYPE

definition below all of the header #include lines, lib/Transforms/...
edition.

This one is tricky for two reasons. We again have a couple of passes
that define something else before the includes as well. I've sunk their
name macros with the DEBUG_TYPE.

Also, InstCombine contains headers that need DEBUG_TYPE, so now those
headers #define and #undef DEBUG_TYPE around their code, leaving them
well formed modular headers. Fixing these headers was a large motivation
for all of these changes, as "leaky" macros of this form are hard on the
modules implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206844 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/InstCombine/InstCombineMulDivRem.cpp

@@ -12,7 +12,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "instcombine"
 #include "InstCombine.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/IR/IntrinsicInst.h"
@@ -20,6 +19,8 @@
 using namespace llvm;
 using namespace PatternMatch;
 
+#define DEBUG_TYPE "instcombine"
+
 
 /// simplifyValueKnownNonZero - The specific integer value is used in a context
 /// where it is known to be non-zero.  If this allows us to simplify the