Hi,
This small patch enables libsanitizer on ARM.
It has been tested successfully on cortex-a9 hardware (via the GCC testsuite).

I have chosen to bundle -funwind-table with -fsanitize=* so that a
useful backtrace can be printed to the user in case of error,
otherwise the reporting is limited to one line belonging to
libsanitizer.so.

Note that the testsuite currently fails when executing under qemu:
- support of /proc/self/maps does not conform to the kernel format.
  One extra space is missing from some lines, which confuses libsanitizer.
  Patch proposed to upstream qemu:
  http://lists.gnu.org/archive/html/qemu-devel/2013-02/msg03051.html

- qemu reserves some memory space by default, conflicting with
libsanitizer needs.
  Workaround: invoke qemu with -R 0

- libsanitizer detects if its output is a tty, and when GCC testsuite
is executed under qemu, libsanitizer concludes that it is actually
running under a tty, and adds beautyfying characters which confuse
dejanu.


OK?

Christophe.

2013-03-27  Christophe Lyon <christophe.lyon@linaro.org>

    gcc/
    * config/arm/arm.c (arm_asan_shadow_offset): New function.
    (TARGET_ASAN_SHADOW_OFFSET): Define.
    * config/arm/linux-eabi.h (ASAN_CC1_SPEC): Define.
    (LINUX_OR_ANDROID_CC): Add ASAN_CC1_SPEC.

    libsanitizer/
    * configure.tgt: Add ARM pattern.