ccc: Recognize -isystem.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64776 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/ccc/ccclib/Arguments.py b/tools/ccc/ccclib/Arguments.py
index 6cda01b..dc9605a 100644
--- a/tools/ccc/ccclib/Arguments.py
+++ b/tools/ccc/ccclib/Arguments.py
@@ -620,6 +620,7 @@
         self.idirafterOption = self.addOption(JoinedOrSeparateOption('-idirafter', self.iGroup))
         self.imacrosOption = self.addOption(JoinedOrSeparateOption('-imacros', self.iGroup))
         self.iprefixOption = self.addOption(JoinedOrSeparateOption('-iprefix', self.iGroup))
+        self.isystem = self.addOption(JoinedOrSeparateOption('-isystem', self.iGroup))
         self.iwithprefixOption = self.addOption(JoinedOrSeparateOption('-iwithprefix', self.iGroup))
         self.iwithprefixbeforeOption = self.addOption(JoinedOrSeparateOption('-iwithprefixbefore', self.iGroup))
         self.addOption(JoinedOrSeparateOption('-iquote', self.iGroup))