Set correct symbol ids when referring to GLSL built-ins

The symbol ids are fetched from the symbol table. A new utility
function is added to make this more convenient.

BUG=angleproject:1490
TEST=angle_unittests, angle_end2end_tests

Change-Id: I780430e3386f6599503d8290c568ca9bc9cad147
Reviewed-on: https://chromium-review.googlesource.com/559535
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/UseInterfaceBlockFields.cpp b/src/compiler/translator/UseInterfaceBlockFields.cpp
index bd9666f..78529dc 100644
--- a/src/compiler/translator/UseInterfaceBlockFields.cpp
+++ b/src/compiler/translator/UseInterfaceBlockFields.cpp
@@ -35,7 +35,7 @@
             name = name.substr(0, pos);
         }
     }
-    TIntermSymbol *symbol = ReferToGlobalSymbol(name, symbolTable);
+    TIntermSymbol *symbol = ReferenceGlobalVariable(name, symbolTable);
     if (var.isArray())
     {
         for (unsigned int i = 0u; i < var.arraySize; ++i)
@@ -77,7 +77,7 @@
         else if (block.arraySize > 0u)
         {
             TString name(block.instanceName.c_str());
-            TIntermSymbol *arraySymbol = ReferToGlobalSymbol(name, symbolTable);
+            TIntermSymbol *arraySymbol = ReferenceGlobalVariable(name, symbolTable);
             for (unsigned int i = 0u; i < block.arraySize; ++i)
             {
                 TIntermBinary *elementSymbol =
@@ -88,7 +88,7 @@
         else
         {
             TString name(block.instanceName.c_str());
-            TIntermSymbol *blockSymbol = ReferToGlobalSymbol(name, symbolTable);
+            TIntermSymbol *blockSymbol = ReferenceGlobalVariable(name, symbolTable);
             InsertUseCode(block, blockSymbol, sequence);
         }
     }