Revert r300889, r300906, r300935, r300939

At least one of the ARM bots is still broken:
Command Output (stderr):
--
/home/buildslave/buildslave/clang-cmake-armv7-a15-full/llvm/projects/compiler-rt/test/asan/TestCases/Posix/strchr.c:31:12: error: expected string not found in input
 // CHECK: strchr.c:[[@LINE-2]]
           ^
<stdin>:3:59: note: scanning from here
==16297==ERROR: AddressSanitizer: SEGV on unknown address 0xb5add000 (pc 0xb6dccaa4 bp 0xbe8c19c8 sp 0xbe8c1570 T0)
                                                          ^
<stdin>:3:59: note: with expression "@LINE-2" equal to "29"
==16297==ERROR: AddressSanitizer: SEGV on unknown address 0xb5add000 (pc 0xb6dccaa4 bp 0xbe8c19c8 sp 0xbe8c1570 T0)
                                                          ^
<stdin>:5:57: note: possible intended match here
 #0 0xb6dccaa3 in strlen /build/glibc-f8FFOS/glibc-2.23/string/../sysdeps/arm/armv6t2/strlen.S:82

Try to fix by reverting r300889 and subsequent fixes:
Revert "[asan] Fix test by removing "The signal is caused" check."
Revert "[asan] Fix test on ppc64le-linux by checking "UNKNOWN memory access""
Revert "[asan] Match BUS and SIGV to fix test on Darwin"
Revert "[asan] Optimize strchr for strict_string_checks=false"

llvm-svn: 300955