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/PruneEmptyDeclarations.cpp b/src/compiler/translator/PruneEmptyDeclarations.cpp
index 133130d..7ec4347 100644
--- a/src/compiler/translator/PruneEmptyDeclarations.cpp
+++ b/src/compiler/translator/PruneEmptyDeclarations.cpp
@@ -9,6 +9,9 @@
 
 #include "compiler/translator/IntermNode.h"
 
+namespace sh
+{
+
 namespace
 {
 
@@ -106,3 +109,5 @@
 {
     PruneEmptyDeclarationsTraverser::apply(root);
 }
+
+}  // namespace sh