[PATCH][x86_64] Convert indirect call via GOT to direct when possible

[Cary Coutant]

>> Do you need to check R_X86_64_REX_GOTPCRELX for branch?
>
> Ok, patch changed to not check for this and refactored a bit.

+# x86_64_indirect_call_to_direct.sh -- a test for indirect call(jump) to direct
+# conversion.
+
+# Copyright (C) 2016 onwards Free Software Foundation, Inc.

I don't think "onwards" is a valid way of expressing copyright dates.
I haven't found any mention of it in the Gnu coding standards, the GPL
documentation, or in any existing sources. (Maybe I missed a policy
change?)

A range of years (e.g., "2012-2016") is only valid when the file was
updated in each of the years in the range. So a blanket "onwards" is
inappropriate for a file that probably won't get touched every year,
even if it is a valid way of expressing a range.

-cary