[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/Vectorize/SLPVectorizer.cpp

@@ -15,9 +15,6 @@
 //  "Loop-Aware SLP in GCC" by Ira Rosen, Dorit Nuzman, Ayal Zaks.
 //
 //===----------------------------------------------------------------------===//
-#define SV_NAME "slp-vectorizer"
-#define DEBUG_TYPE "SLP"
-
 #include "llvm/Transforms/Vectorize.h"
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/PostOrderIterator.h"
@@ -47,6 +44,9 @@
 
 using namespace llvm;
 
+#define SV_NAME "slp-vectorizer"
+#define DEBUG_TYPE "SLP"
+
 static cl::opt<int>
     SLPCostThreshold("slp-threshold", cl::init(0), cl::Hidden,
                      cl::desc("Only vectorize if you gain more than this "