[asan][test] Fix SED issues with macOS (BSD)

[rsundahl]

Summary

SED differs between GNU and BSD in handling semicolon and the use of
'\n' in regex patterns. For macOS we can't use these GNU extensions.

rdar://102686948

[yln]

LGTM & thanks from my side!

Previous switch from grep to sed to make Windows bot work by @vitalybuka here: a27089101edf
@vitalybuka, can you confirm this still works for Windows and the other environments you care about?

[rsundahl]

FWIW: I tested this sed syntax on latest Alpine, CentOS, Debian and Ubuntu and all ok.

[thetruestblue]

Thanks for fixing this quick, @rsundahl.

[thakis]

Building on macOS has been broken for close to a week now. Is this blocked on anything? If so, can we revert the original change for now, to unbreak the build?

compiler-rt/test/asan/TestCases/Darwin/interface_symbols_darwin.cpp

 // RUN:  | grep -o "\(__asan_\|__ubsan_\|__sancov_\|__sanitizer_\)[^ ]*"       \
 // RUN:  | grep -v "__sanitizer_syscall"                                       \
 // RUN:  | grep -v "__sanitizer_weak_hook"                                     \
 // RUN:  | grep -v "__sanitizer_mz"                                            \
 // RUN:  | grep -v "__sancov_lowest_stack"                                     \
 // RUN:  | sed -e "s/__asan_version_mismatch_check_v[0-9]+/__asan_version_mismatch_check/" \
 // RUN:  > %t.exports
 //
-// RUN: sed ':a;N;$!ba;s/([\n ]*/(/g'                                             \
+// note: SED differs between GNU and BSD in handling semicolon and the use of
+//       '\n' in regex patterns. For macOS we must change this GNU syntax:
+//           sed -e ':a' -e 'N' -e '$!ba'
+//       to a form that both GNU and BSD can agree upon (below).
+//
+// RUN:  sed -e ':a' -e 'N' -e '$!ba'                                             \
+// RUN:      -e 's/ //g'                                                          \
+// RUN:      -e ':b' -e 's/\n\n/\n/g' -e 'tb'                                     \
+// RUN:      -e 's/(\n/(/g'                                                       \
 // RUN:  %t.asan_interface.inc                                                    \
 // RUN:  %p/../../../../lib/ubsan/ubsan_interface.inc                             \
 // RUN:  %p/../../../../lib/sanitizer_common/sanitizer_common_interface.inc       \
 // RUN:  %p/../../../../lib/sanitizer_common/sanitizer_common_interface_posix.inc \
 // RUN:  %p/../../../../lib/sanitizer_common/sanitizer_coverage_interface.inc     \
 // RUN:  | grep -e "INTERFACE_\(WEAK_\)\?FUNCTION"                                \
 // RUN:  | grep -v "__sanitizer_weak_hook"                                        \
 // RUN:  | sed -e "s/.*(//" -e "s/).*//" > %t.imports