fixed a few SPIR-V generation errors

Bug: skia:
Change-Id: Ica79d36e32dcfbfc68a6238c9fa0b2a8dcfa20bb
Reviewed-on: https://skia-review.googlesource.com/78040
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
diff --git a/src/sksl/SkSLSPIRVCodeGenerator.h b/src/sksl/SkSLSPIRVCodeGenerator.h
index 63d5a40..0d51af5 100644
--- a/src/sksl/SkSLSPIRVCodeGenerator.h
+++ b/src/sksl/SkSLSPIRVCodeGenerator.h
@@ -90,6 +90,7 @@
 
     enum SpecialIntrinsic {
         kAtan_SpecialIntrinsic,
+        kMod_SpecialIntrinsic,
         kSubpassLoad_SpecialIntrinsic,
         kTexelFetch_SpecialIntrinsic,
         kTexture_SpecialIntrinsic,