[IR] Don't call assertModuleIsMaterialized in release builds

[craig.topper]

Summary

To fix a release vs debug build linking error, r259695 made the body of assertModuleIsMaterialized empty if Value.cpp gets compiled in a release build. This way any code compiled as a debug build can still link against a release version of the function.

This patch takes this a step farther and removes all calls to it from Value.h in any code that includes it in a relase build.

This shrinks the opt binary on my macbook build by 17240 bytes.

[craig.topper]

Make the patch less intrusive by renaming the existing method to Impl and putting a inline method around a call to contain the #ifndefs.

include/llvm/IR/Value.h

public:
   //
   // Materializing a function can introduce new uses, so these methods come in
   // two variants:
   // The methods that start with materialized_ check the uses that are
   // currently known given which functions are materialized. Be very careful
   // when using them since you might not get all uses.
   // The methods that don't start with materialized_ assert that modules is
   // fully materialized.
-  void assertModuleIsMaterialized() const;
+  void assertModuleIsMaterializedImpl() const;
+  // This indirection exists so we can keep assertModuleIsMaterializedImpl()
+  // around in release builds of Value.cpp to be linked with other code built
+  // in debug mode. But this avoids calling it in any of the release built code.
+  void assertModuleIsMaterialized() const {
+#ifndef NDEBUG
+    assertModuleIsMaterializedImpl();
+#endif
+  }
 
   bool use_empty() const {
     assertModuleIsMaterialized();
     return UseList == nullptr;
   }
 
   typedef use_iterator_impl<Use> use_iterator;
   typedef use_iterator_impl<const Use> const_use_iterator;

lib/IR/Value.cpp

void Value::takeName(Value *V) {
   setValueName(V->getValueName());
   V->setValueName(nullptr);
   getValueName()->setValue(this);
 
   if (ST)
     ST->reinsertValue(this);
 }
 
-void Value::assertModuleIsMaterialized() const {
+void Value::assertModuleIsMaterializedImpl() const {
 #ifndef NDEBUG
   const GlobalValue *GV = dyn_cast<GlobalValue>(this);
   if (!GV)
     return;
   const Module *M = GV->getParent();
   if (!M)
     return;
   assert(M->isMaterialized());