Change some dyn_cast to more apropriate isa. NFC

llvm-svn: 357773
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 7887ce1..fe22e94 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1231,7 +1231,7 @@
   // GlobalVariable or Function, i.e., as GlobalValue.
   if (!GV->hasGlobalUnnamedAddr() || !GV->hasInitializer() ||
       !GV->isConstant() || !GV->isDiscardableIfUnused() ||
-      !dyn_cast<GlobalValue>(GV->getOperand(0)))
+      !isa<GlobalValue>(GV->getOperand(0)))
     return false;
 
   // To be a got equivalent, at least one of its users need to be a constant