tgsi: add tgsi_declaration fields for centroid sampling, invariant optimization

(cherry picked from commit 434e255eae)

src/gallium/auxiliary/tgsi/tgsi_build.c

@@ -119,6 +119,8 @@ tgsi_default_declaration( void )
    declaration.UsageMask = TGSI_WRITEMASK_XYZW;
    declaration.Interpolate = TGSI_INTERPOLATE_CONSTANT;
    declaration.Semantic = 0;
+   declaration.Centroid = 0;
+   declaration.Invariant = 0;
    declaration.Padding = 0;
    declaration.Extended = 0;
 

src/gallium/auxiliary/tgsi/tgsi_dump.c

@@ -248,6 +248,14 @@ iter_declaration(
    TXT( ", " );
    ENM( decl->Declaration.Interpolate, interpolate_names );
 
+   if (decl->Declaration.Centroid) {
+      TXT( ", CENTROID" );
+   }
+
+   if (decl->Declaration.Invariant) {
+      TXT( ", INVARIANT" );
+   }
+
    EOL();
 
    return TRUE;

src/gallium/include/pipe/p_shader_tokens.h

@@ -85,7 +85,9 @@ struct tgsi_declaration
    unsigned UsageMask   : 4;  /* bitmask of TGSI_WRITEMASK_x flags */
    unsigned Interpolate : 4;  /* TGSI_INTERPOLATE_ */
    unsigned Semantic    : 1;  /* BOOL, any semantic info? */
-   unsigned Padding     : 6;
+   unsigned Centroid    : 1;  /* centroid sampling */
+   unsigned Invariant   : 1;  /* invariant optimization */
+   unsigned Padding     : 4;
    unsigned Extended    : 1;  /* BOOL */
 };