Replace remaining usage of TName with TSymbol

TName used to contain just a subset of the information stored in
TSymbol. It makes more sense to use TSymbol directly instead of
converting it to TName.

This also improves type safety a bit by making some functions only
take in TVariable or TFunction instead of the more generic TName.

BUG=angleproject:2267
TEST=angle_unittests

Change-Id: Icb46923c25d33ebbbbc06ddc487da25957dda771
Reviewed-on: https://chromium-review.googlesource.com/829143
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/VersionGLSL.cpp b/src/compiler/translator/VersionGLSL.cpp
index 8168876..e9d654c 100644
--- a/src/compiler/translator/VersionGLSL.cpp
+++ b/src/compiler/translator/VersionGLSL.cpp
@@ -7,6 +7,7 @@
 #include "compiler/translator/VersionGLSL.h"
 
 #include "angle_gl.h"
+#include "compiler/translator/Symbol.h"
 
 namespace sh
 {
@@ -76,7 +77,7 @@
 
 void TVersionGLSL::visitSymbol(TIntermSymbol *node)
 {
-    if (node->getSymbol() == "gl_PointCoord")
+    if (node->variable().symbolType() == SymbolType::BuiltIn && node->getName() == "gl_PointCoord")
     {
         ensureVersionIsAtLeast(GLSL_VERSION_120);
     }