compiler: rename SYSTEM_VALUE_VARYING_COORD

And add corresponding enums for different sorts of varying
interpolation.

Signed-off-by: Rob Clark <robdclark@chromium.org>

src/compiler/shader_enums.c

@@ -247,7 +247,10 @@ gl_system_value_name(gl_system_value sysval)
      ENUM(SYSTEM_VALUE_DEVICE_INDEX),
      ENUM(SYSTEM_VALUE_VIEW_INDEX),
      ENUM(SYSTEM_VALUE_VERTEX_CNT),
-     ENUM(SYSTEM_VALUE_VARYING_COORD),
+     ENUM(SYSTEM_VALUE_BARYCENTRIC_PIXEL),
+     ENUM(SYSTEM_VALUE_BARYCENTRIC_SAMPLE),
+     ENUM(SYSTEM_VALUE_BARYCENTRIC_CENTROID),
+     ENUM(SYSTEM_VALUE_BARYCENTRIC_SIZE),
    };
    STATIC_ASSERT(ARRAY_SIZE(names) == SYSTEM_VALUE_MAX);
    return NAME(sysval);