[IR] Refactor attribute methods in Function class (NFC)

Rename the functions that query the optimization kind attributes.

Differential revision: https://reviews.llvm.org/D60287

llvm-svn: 357731
diff --git a/llvm/lib/Analysis/GlobalsModRef.cpp b/llvm/lib/Analysis/GlobalsModRef.cpp
index 2ded6be..2c967c8 100644
--- a/llvm/lib/Analysis/GlobalsModRef.cpp
+++ b/llvm/lib/Analysis/GlobalsModRef.cpp
@@ -513,7 +513,7 @@
         break;
       }
 
-      if (F->isDeclaration() || F->optForNone()) {
+      if (F->isDeclaration() || F->hasOptNone()) {
         // Try to get mod/ref behaviour from function attributes.
         if (F->doesNotAccessMemory()) {
           // Can't do better than that!
@@ -566,7 +566,7 @@
       // Don't prove any properties based on the implementation of an optnone
       // function. Function attributes were already used as a best approximation
       // above.
-      if (Node->getFunction()->optForNone())
+      if (Node->getFunction()->hasOptNone())
         continue;
 
       for (Instruction &I : instructions(Node->getFunction())) {