Remove LINEMAP_POSITION_FOR_COLUMN macro (issue4874043)

[Tom Tromey]

>>>>> "Gabriel" == Gabriel Charette <gchare@google.com> writes:

Gabriel> Removed LINEMAP_POSITION_FOR_COLUMN, it did the EXACT same
Gabriel> thing as linemap_position_for_column, so maintaining both in
Gabriel> parallel seems like overkill to me. The only thing I can think
Gabriel> of is that it's more optimal as it's inlined (but if that's
Gabriel> really needed we can always make linemap_position_for_column an
Gabriel> inline function directly).

I am sympathetic to this, but nobody is likely to do the performance
tests post-patch.

The libcpp parts are ok if it doesn't cause a noticeable slowdown in the
GCC bootstrap.

I can't approve the changes outside of libcpp.
Also, you didn't write a ChangeLog entry for those.

Tom