Fix egrep regexp in new error message tests to work with Linux assert messages.
Fix egrep regexp in new error message tests to work with Linux assert messages.


Former-commit-id: 5ce45149ed298fc03be8a90fd88e76cd232b1dd9
darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide