translator: Scope all classes with "sh".

I was seeing an odd problem with our PoolAlloc conflicting with the
glslang/Vulkan TIntermNode, so the fix was to move everything to a
separate namespace.

The bison grammars are also regenerated. No functional changes.

BUG=angleproject:1576

Change-Id: I959c7afe4c092f0d458432c07b4dcee4d39513f3
Reviewed-on: https://chromium-review.googlesource.com/408267
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/ConstantUnion.cpp b/src/compiler/translator/ConstantUnion.cpp
index b4074bf..1ee3f64 100644
--- a/src/compiler/translator/ConstantUnion.cpp
+++ b/src/compiler/translator/ConstantUnion.cpp
@@ -11,6 +11,9 @@
 #include "common/mathutil.h"
 #include "compiler/translator/Diagnostics.h"
 
+namespace sh
+{
+
 namespace
 {
 
@@ -620,3 +623,5 @@
 
     return returnValue;
 }
+
+}  // namespace sh