intel/compiler: Move the destructor from vec4_visitor to backend_shader

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/intel/compiler/brw_shader.cpp

@@ -673,6 +673,10 @@ backend_shader::backend_shader(const struct brw_compiler *compiler,
    stage_abbrev = _mesa_shader_stage_to_abbrev(stage);
 }
 
+backend_shader::~backend_shader()
+{
+}
+
 bool
 backend_reg::equals(const backend_reg &r) const
 {

src/intel/compiler/brw_shader.h

@@ -197,6 +197,7 @@ protected:
                   struct brw_stage_prog_data *stage_prog_data);
 
 public:
+   virtual ~backend_shader();
 
    const struct brw_compiler *compiler;
    void *log_data; /* Passed to compiler->*_log functions */

src/intel/compiler/brw_vec4.h

@@ -72,7 +72,6 @@ public:
 		void *mem_ctx,
                 bool no_spills,
                 int shader_time_index);
-   virtual ~vec4_visitor();
 
    dst_reg dst_null_f()
    {

src/intel/compiler/brw_vec4_visitor.cpp

@@ -1883,10 +1883,6 @@ vec4_visitor::vec4_visitor(const struct brw_compiler *compiler,
    this->uniforms = 0;
 }
 
-vec4_visitor::~vec4_visitor()
-{
-}
-
 
 void
 vec4_visitor::fail(const char *format, ...)