[Support] exit with custom return code for SIGPIPE
Summary:
We tell the user to file a bug report on LLVM right now, and
SIGPIPE isn't LLVM's fault so our error message is wrong.
Allows frontends to detect SIGPIPE from writing to closed readers.
This can be seen commonly from piping into head, tee, or split.
Fixes PR25349, rdar://problem/
14285346, b/
77310947
Reviewers: jfb
Reviewed By: jfb
Subscribers: majnemer, kristina, llvm-commits, thakis, srhines
Differential Revision: https://reviews.llvm.org/D53000
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344372
91177308-0d34-0410-b5e6-
96231b3b80d8