switched SPIR-V vertexid to vertexindex

Bug: skia:
Change-Id: I32c10e2874feea63d7fa048057ef57e27d5874bc
Reviewed-on: https://skia-review.googlesource.com/115880
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
(cherry picked from commit 9eded2c211773133b86a964b357404ae6b021d7d)
Reviewed-on: https://skia-review.googlesource.com/115941
Reviewed-by: Hal Canary <halcanary@google.com>
diff --git a/src/sksl/SkSLCompiler.h b/src/sksl/SkSLCompiler.h
index eb2fc45..5c57507 100644
--- a/src/sksl/SkSLCompiler.h
+++ b/src/sksl/SkSLCompiler.h
@@ -25,8 +25,8 @@
 #define SK_TRANSFORMEDCOORDS2D_BUILTIN 10005
 #define SK_TEXTURESAMPLERS_BUILTIN     10006
 #define SK_FRAGCOORD_BUILTIN              15
-#define SK_VERTEXID_BUILTIN                5
-#define SK_INSTANCEID_BUILTIN              6
+#define SK_VERTEXID_BUILTIN               42
+#define SK_INSTANCEID_BUILTIN             43
 #define SK_CLIPDISTANCE_BUILTIN            3
 #define SK_INVOCATIONID_BUILTIN            8
 #define SK_POSITION_BUILTIN                0
diff --git a/src/sksl/sksl_vert.inc b/src/sksl/sksl_vert.inc
index da2a1a2..86db5d2 100644
--- a/src/sksl/sksl_vert.inc
+++ b/src/sksl/sksl_vert.inc
@@ -8,7 +8,7 @@
     layout(builtin=3) float sk_ClipDistance[1];
 };
 
-layout(builtin=5) in int sk_VertexID;
-layout(builtin=6) in int sk_InstanceID;
+layout(builtin=42) in int sk_VertexID;
+layout(builtin=43) in int sk_InstanceID;
 
 )