[scan-build] Accept -fno-objc-arc as well as -fobjc-arc.

This is how Xcode lets individual files be marked as non-ARC when the rest
of the project is ARC-enabled, so this is necessary for scan-build xcodebuild.

Patch by Paul Eipper!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162497 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/scan-build/ccc-analyzer b/tools/scan-build/ccc-analyzer
index c7636f9..216dc9d 100755
--- a/tools/scan-build/ccc-analyzer
+++ b/tools/scan-build/ccc-analyzer
@@ -346,6 +346,7 @@
 
 my %CompilerLinkerOptionMap = (
   '-fobjc-arc' => 0,
+  '-fno-objc-arc' => 0,
   '-fobjc-abi-version' => 0, # This is really a 1 argument, but always has '='
   '-fobjc-legacy-dispatch' => 0,
   '-mios-simulator-version-min' => 0, # This really has 1 argument, but always has '='