[dump] Remove NDEBUG from test to enable dump methods [NFC]

Summary:
Add LLVM_FORCE_ENABLE_DUMP cmake option, and use it along with
LLVM_ENABLE_ASSERTIONS to set LLVM_ENABLE_DUMP.

Remove NDEBUG and only use LLVM_ENABLE_DUMP to enable dump methods.

Move definition of LLVM_ENABLE_DUMP from config.h to llvm-config.h so
it'll be picked up by public headers.

Differential Revision: https://reviews.llvm.org/D38406

llvm-svn: 315590

llvm/lib/CodeGen/LiveDebugVariables.cpp

@@ -398,7 +398,7 @@ public:
 
 } // end anonymous namespace
 
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+#ifdef LLVM_ENABLE_DUMP
 static void printDebugLoc(const DebugLoc &DL, raw_ostream &CommentOS,
                           const LLVMContext &Ctx) {
   if (!DL)
@@ -1218,7 +1218,7 @@ bool LiveDebugVariables::doInitialization(Module &M) {
   return Pass::doInitialization(M);
 }
 
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+#ifdef LLVM_ENABLE_DUMP
 LLVM_DUMP_METHOD void LiveDebugVariables::dump() const {
   if (pImpl)
     static_cast<LDVImpl*>(pImpl)->print(dbgs());