glsl: Hide many classes local to individual .cpp files in anon namespaces.

This gives the compiler the chance to inline and not export class symbols
even in the absence of LTO.  Saves about 60kb on disk.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@.intel.com>

src/glsl/loop_analysis.cpp

@@ -102,6 +102,7 @@ loop_variable_state::insert(ir_if *if_stmt)
    return t;
 }
 
+namespace {
 
 class loop_analysis : public ir_hierarchical_visitor {
 public:
@@ -128,6 +129,7 @@ public:
    exec_list state;
 };
 
+} /* anonymous namespace */
 
 loop_analysis::loop_analysis(loop_state *loops)
    : loops(loops), if_statement_depth(0), current_assignment(NULL)