Clarify error checking function names in the GLSL parser

Most error checking functions in ParseContext used to follow a format
like <property>ErrorCheck. Sometimes this function would check that
the node/value would have <property>, sometimes it would check that
the node/value would not have it, which was confusing. Change most of
these functions to use a lot more descriptive names, which clearly
communicate what they are checking for.

Also includes a bit of refactoring in constructorErrorCheck(), so that
the function only checks for errors rather than also setting the type
of the constructor node.

Also make TType::arraySize unsigned, and return a sanitized size from
checkIsValidArraySize() instead of using an output parameter.

BUG=angleproject:911
TEST=angle_unittests

Change-Id: Id9767b8c79594ad3f782f801ea68eb96df721a31
Reviewed-on: https://chromium-review.googlesource.com/367070
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
diff --git a/src/compiler/translator/util.cpp b/src/compiler/translator/util.cpp
index 41276c6..bd3e484 100644
--- a/src/compiler/translator/util.cpp
+++ b/src/compiler/translator/util.cpp
@@ -504,7 +504,7 @@
 
     VarT variable;
     variable.name = name.c_str();
-    variable.arraySize = static_cast<unsigned int>(type.getArraySize());
+    variable.arraySize = type.getArraySize();
 
     if (!structure)
     {