Fixed error message for exceeding maximum struct nesting.

Fixed error message for exceeding maximum struct nesting.

It got broken in r2423.
We were referring to field-name as struct-name.
This patch fixes the regression and also improves the error message
by adding the field-name.

BUG=459
R=kbr@chromium.org

Committed: https://code.google.com/p/angleproject/source/detail?r=e06002a

[kbr1, 2013-08-13 20:57:57]

LGTM

I don't suppose it's possible to add a test for this?

[Alok Priyadarshi, 2013-08-13 21:01:41]

On 2013/08/13 20:57:57, kbr1 wrote:
> LGTM
> 
> I don't suppose it's possible to add a test for this?

To be clear we just broke the error message. We have a WebGL conformance test
for the main functionality here:
https://www.khronos.org/registry/webgl/conformance-suites/1.0.1/conformance/g...

If we want to test that the error message contains field-name and struct-name, I
guess that could be done. Although we do not have a good setup to do compiler
unit-tests.

[kbr1, 2013-08-13 21:04:04]

It isn't feasible to require anything in the error messages at the WebGL level,
but if we could start working on a compiler unit test harness, that would be
ideal. I recall you adding some excellent tests for the preprocessor, and it
would be great if the compiler was as well tested.

[Alok Priyadarshi, 2013-08-13 21:32:03]

On 2013/08/13 21:04:04, kbr1 wrote:
> It isn't feasible to require anything in the error messages at the WebGL
level,
> but if we could start working on a compiler unit test harness, that would be
> ideal. I recall you adding some excellent tests for the preprocessor, and it
> would be great if the compiler was as well tested.

There are some build issues with the compiler unit harness that I hope to
address soon.

[Alok Priyadarshi, 2013-08-13 21:35:44]

Committed patchset #2 manually as re06002a (presubmit successful).