Add NV_fragment_shader_interlock support.

The main purpose for having NV_fragment_shader_interlock
extension is because that extension is also for GLES31 while
the ARB extension is for GL only.

Reviewed-by: Plamena Manolova <plamena.manolova@intel.com>

src/compiler/glsl/builtin_functions.cpp

@@ -519,6 +519,12 @@ supports_arb_fragment_shader_interlock(const _mesa_glsl_parse_state *state)
    return state->ARB_fragment_shader_interlock_enable;
 }
 
+static bool
+supports_nv_fragment_shader_interlock(const _mesa_glsl_parse_state *state)
+{
+   return state->NV_fragment_shader_interlock_enable;
+}
+
 static bool
 shader_clock(const _mesa_glsl_parse_state *state)
 {
@@ -3331,6 +3337,18 @@ builtin_builder::create_builtins()
                    supports_arb_fragment_shader_interlock),
                 NULL);
 
+   add_function("beginInvocationInterlockNV",
+                _invocation_interlock(
+                   "__intrinsic_begin_invocation_interlock",
+                   supports_nv_fragment_shader_interlock),
+                NULL);
+
+   add_function("endInvocationInterlockNV",
+                _invocation_interlock(
+                   "__intrinsic_end_invocation_interlock",
+                   supports_nv_fragment_shader_interlock),
+                NULL);
+
    add_function("anyInvocationARB",
                 _vote("__intrinsic_vote_any", vote),
                 NULL);