Refactor a bit of duplicated code to useIntegratedAs.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177299 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/ToolChain.cpp b/lib/Driver/ToolChain.cpp
index 21015a6..29aecf2 100644
--- a/lib/Driver/ToolChain.cpp
+++ b/lib/Driver/ToolChain.cpp
@@ -32,6 +32,12 @@
  return D;
 }
 
+bool ToolChain::useIntegratedAs(const ArgList &Args) const {
+  return Args.hasFlag(options::OPT_integrated_as,
+                      options::OPT_no_integrated_as,
+                      IsIntegratedAssemblerDefault());
+}
+
 std::string ToolChain::getDefaultUniversalArchName() const {
   // In universal driver terms, the arch name accepted by -arch isn't exactly
   // the same as the ones that appear in the triple. Roughly speaking, this is