Parsing should accept all values between 0 and 0xFFFFFFFF as specified in
ESSL 3.00 section 4.1.3.

When a signed literal is parsed, it's interpreted as if it specifies the
bit pattern of a two's complement integer. For example, parsing
"0xFFFFFFFF" results in -1. Decimal literals behave the same way, so for
example parsing "3000000000" results in -1294967296.

This change affects parsing of literals in ESSL 1.00 as well. In ESSL
3.00, an out-of-range integer literal now generates a compiler error.

Unit tests are added based on examples in the ESSL 3.00 spec and one
example in GLSL 4.5 spec that ESSL should match.

BUG=541550
TEST=angle_unittests

Change-Id: I82f8ef5cfa2881019a3f80d77ff99707d61c000d
Reviewed-on: https://chromium-review.googlesource.com/305420Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Corentin Wallez <cwallez@google.com>