asan: Don’t pad the CrashpadInfo struct with a red zone
asan: Don’t pad the CrashpadInfo struct with a red zone

MachOImageReader::GetCrashpadInfo() expects the CrashpadInfo struct to
be the only thing in a __DATA,__crashpad_info section, and enforces this
by checking that the section’s size matches the size declared in the
struct’s size_ field.

Under AddressSanitizer, a red zone follows the structure. While not
reflected in the size of the structure, it is reflected in the size of
the section, causing MachOImageReader::GetCrashpadInfo() to reject the
CrashpadInfo on the assumption that something else is present in the
section.

By specifying an alignment greater than the minimum red zone size of 32
bytes, red zone generation can be suppressed.

TEST=crashpad_snapshot_test
BUG=crashpad:44
R=glider@chromium.org, rsesek@chromium.org

Review URL: https://codereview.chromium.org/1296523003 .

chromium/crashpad,Chilledheart/crashpad,Chilledheart/crashpad,Chilledheart/crashpad,chromium/crashpad,atom/crashpad,atom/crashpad,chromium/crashpad,atom/crashpad