PR c++/69145
* files.c (cpp_included_before): If IS_ADHOC_LOC (location), lookup
real location from the line_table.
* g++.dg/ext/pr69145-1.C: New test.
* g++.dg/ext/pr69145-2-very-long-filename.cc: New file.
* g++.dg/ext/pr69145-2.h: New file.
From-SVN: r232150
