Update TargetInfo::getDefaultCallingConv()'s documentation too.

Author: hvdijk

clang/include/clang/Basic/TargetInfo.h

@@ -1693,8 +1693,11 @@ class TargetInfo : public TransferrableTargetInfo,
   /// Controls if __arithmetic_fence is supported in the targeted backend.
   virtual bool checkArithmeticFenceSupported() const { return false; }
 
-  /// Gets the default calling convention for the given target and
-  /// declaration context.
+  /// Gets the default calling convention for the given target.
+  ///
+  /// This function does not take into account any user options to override the
+  /// default calling convention. For that, see
+  /// ASTContext::getDefaultCallingConvention().
   virtual CallingConv getDefaultCallingConv() const {
     // Not all targets will specify an explicit calling convention that we can
     // express.  This will always do the right thing, even though it's not