Fix -Wcast-qual warnings.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@101786 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index 427bd6a..0f7dca2 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -431,8 +431,10 @@
 
   const driver::ArgStringList &CCArgs = Cmd->getArguments();
   llvm::OwningPtr<CompilerInvocation> CI(new CompilerInvocation);
-  CompilerInvocation::CreateFromArgs(*CI, (const char**) CCArgs.data(),
-                                     (const char**) CCArgs.data()+CCArgs.size(),
+  CompilerInvocation::CreateFromArgs(*CI,
+                                     const_cast<const char **>(CCArgs.data()),
+                                     const_cast<const char **>(CCArgs.data()) +
+                                       CCArgs.size(),
                                      *Diags);
 
   // Override any files that need remapping