Implemented new restrictions on nesting of structs in WebGL shaders.

Implemented new restrictions on nesting of structs in WebGL shaders.
Added previously missing check for embedded structs; even though these
attempts would be caught by an underlying GLSL compiler, the shader
validator should not let them through.

BUG=http://code.google.com/p/angleproject/issues/detail?id=235
TEST=WebGL conformance tests
Committed: http://code.google.com/p/angleproject/source/detail?r=809

[kbr1, 2011-10-26 23:30:05]

The new limitations are specified here:
http://www.khronos.org/registry/webgl/specs/latest/

The new code has been verified against tests just added to the WebGL conformance
suite.

Please review. Thanks.

[Alok Priyadarshi, 2011-10-27 04:05:12]

lgtm

just a couple nits.

http://codereview.appspot.com/5327046/diff/1/src/compiler/SymbolTable.cpp
File src/compiler/SymbolTable.cpp (right):

http://codereview.appspot.com/5327046/diff/1/src/compiler/SymbolTable.cpp#new...
src/compiler/SymbolTable.cpp:77: 
empty namespace block

http://codereview.appspot.com/5327046/diff/1/src/compiler/SymbolTable.cpp#new...
src/compiler/SymbolTable.cpp:89: for (TTypeList::const_iterator tl =
getStruct()->begin(); tl != getStruct()->end(); tl++) {
tl++ -> ++tl

[kbr1, 2011-10-27 21:14:40]

http://codereview.appspot.com/5327046/diff/1/src/compiler/SymbolTable.cpp
File src/compiler/SymbolTable.cpp (right):

http://codereview.appspot.com/5327046/diff/1/src/compiler/SymbolTable.cpp#new...
src/compiler/SymbolTable.cpp:77: 
On 2011/10/27 04:05:13, Alok Priyadarshi wrote:
> empty namespace block

Whoops. Fixed.

http://codereview.appspot.com/5327046/diff/1/src/compiler/SymbolTable.cpp#new...
src/compiler/SymbolTable.cpp:89: for (TTypeList::const_iterator tl =
getStruct()->begin(); tl != getStruct()->end(); tl++) {
On 2011/10/27 04:05:13, Alok Priyadarshi wrote:
> tl++ -> ++tl

OK, but the postincrement is used elsewhere in this file.