This patch breaks bootstrap on AIX and probably is a hidden bug on all targets.
With the patch, libbacktrace/xcoff.c fails to compile with the error: /nasfarm/edelsohn/src/src/libbacktrace/xcoff.c: In function 'xcoff_add': /nasfarm/edelsohn/src/src/libbacktrace/xcoff.c:822:13: error: 'incl' may be used uninitialized in this function [-Werror=maybe-uninitialized] filename = incl->filename; ~~~~~~~~~^~~~~~~~~~~~~~~~ /nasfarm/edelsohn/src/src/libbacktrace/xcoff.c:777:22: note: 'incl' was declared here struct xcoff_incl *incl; ^~~~ incl is used immediately above the line that produces the warning -- with no warning. I can provide a pre-processed xcoff.c, if you need it. Thanks, David