disable inline ARM saturated arithmetic assembly for debug builds

disable inline ARM saturated arithmetic assembly for debug builds

When building third_party/WebKit/Source/wtf/asm/SaturatedArithmeticARM.h
in debug builds, we get this error:
cc1plus: warnings being treated as errors
 SaturatedArithmeticARM.h: In function 'int saturatedSet(int, int)':
 SaturatedArithmeticARM.h:70:43: error: asm operand 2 probably doesn't match constraints
 SaturatedArithmeticARM.h:70:43: error: asm operand 3 probably doesn't match constraints

By switching -O0 to -O1 or -O2 in the compile command, the compile
succeeds. So let's disable the inline ARM assembly unless the build
is optimized- gcc defines _OPTIMIZE_=1 in this case.
I think this is a reasonable workaround until we can find a "proper"
solution.

BUG=325746
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=178209

[Mostyn Bramley-Moore, 2014-07-15 08:28:49]

@picksi, eae: PTAL at this tiny fixup for
https://codereview.chromium.org/346913004 - I'm not sure if it's worth digging
deeper to fix the assembly for unoptimized builds?

@eseidel: PTAL for owner approval.

[picksi, 2014-07-15 09:22:51]

lgtm.

Thanks for fixing this. I have a heavy handed solution that builds OK for
non-optimized builds here: 

https://codereview.chromium.org/378253003/

It fixes the compiler's failure to turn a const into something asm friendly by
wrapping the whole thing in a template. It's an ugly fix that drags
implementation details up into LayoutUnit.h - I much prefer this simpler
solution.

[eseidel, 2014-07-15 15:35:44]

lgtm

[commit-bot: I haz the power, 2014-07-15 15:36:21]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mostynb@opera.com/396603002/1

[commit-bot: I haz the power, 2014-07-15 16:47:11]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/1...)

[commit-bot: I haz the power, 2014-07-15 17:53:35]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-07-15 17:53:36]

Try jobs failed on following builders:
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/1...)

[Mostyn Bramley-Moore, 2014-07-15 20:01:59]

The CQ bit was checked by mostynb@opera.com

[commit-bot: I haz the power, 2014-07-15 20:03:25]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mostynb@opera.com/396603002/1

[commit-bot: I haz the power, 2014-07-15 21:11:16]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/1...)

[commit-bot: I haz the power, 2014-07-15 22:16:02]

Change committed as 178209