Add a llvm lit test for NaCl ARM/X86 support for bswap i16, i32, i64.

Add a llvm lit test for NaCl ARM/X86 support for bswap i16, i32, i64.

Slowly trying to promote "dev" intrinsics that are being
tested to be accepted.  Luckily, bswap is supported
without compiler_rt for ARM and x86 at least.

Test at default level and -O0. Also tested by
gcc/testsuite/gcc.dg/builtin-bswap-[1,2,3,4,5].c,
and a couple of other gcc tests.

We may want to blacklist odd argument sizes
like i8, and i1, which the x86 backend won't handle.
The i16 case is also interesting, however, it's easy
to do if you have an i32 bswap.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3378
R=eliben@chromium.org

Committed: https://gerrit.chromium.org/gerrit/gitweb?p=native_client/pnacl-llvm.git;a=commit;h=4fbe1a0

[eliben, 2013-05-08 21:33:03]

lgtm

[Mark Seaborn, 2013-05-08 21:39:53]

https://codereview.chromium.org/14971004/diff/4001/test/NaCl/ARM/intrinsics_b...
File test/NaCl/ARM/intrinsics_bitmanip.ll (right):

https://codereview.chromium.org/14971004/diff/4001/test/NaCl/ARM/intrinsics_b...
test/NaCl/ARM/intrinsics_bitmanip.ll:1: ; RUN: llc -mtriple=armv7-unknown-nacl
-filetype=asm %s -o - | FileCheck %s
Nit: other files in test/NaCl use "-" rather than "_" in filenames

[jvoung (off chromium), 2013-05-09 17:23:49]

https://codereview.chromium.org/14971004/diff/4001/test/NaCl/ARM/intrinsics_b...
File test/NaCl/ARM/intrinsics_bitmanip.ll (right):

https://codereview.chromium.org/14971004/diff/4001/test/NaCl/ARM/intrinsics_b...
test/NaCl/ARM/intrinsics_bitmanip.ll:1: ; RUN: llc -mtriple=armv7-unknown-nacl
-filetype=asm %s -o - | FileCheck %s
On 2013/05/08 21:39:53, Mark Seaborn wrote:
> Nit: other files in test/NaCl use "-" rather than "_" in filenames

Ah right, renamed.

[jvoung (off chromium), 2013-05-09 17:52:40]

Committed patchset #4 manually as r4fbe1a0 (presubmit successful).