Summary:
This fixes a subtle bug in new FileCheck feature added
in r194343. When we search for the first satisfying check-prefix,
we should actually return the first encounter of some check-prefix as a
substring, even if it's not a part of valid check-line. Otherwise
"FileCheck --check-prefix=FOO --check-prefix=BAR" with check file:
FOO not a vaild check-line
FOO: foo
BAR: bar
incorrectly accepted file:
fog
bar
as it skipped the first two encounters of FOO, matching only BAR: line.
Reviewers: arsenm, dsanders
Reviewed By: dsanders
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2166
llvm-svn: 194565
