Update spirv-tools known-good
diff --git a/known_good.json b/known_good.json
index a458769..a943c8f 100644
--- a/known_good.json
+++ b/known_good.json
@@ -5,14 +5,14 @@
       "site" : "github",
       "subrepo" : "KhronosGroup/SPIRV-Tools",
       "subdir" : "External/spirv-tools",
-      "commit" : "2ff54e34ed3730477401f340c71ae14b7641031e"
+      "commit" : "26c1b8878315a7a5c188df45e0bc236bb222b698"
     },
     {
       "name" : "spirv-tools/external/spirv-headers",
       "site" : "github",
       "subrepo" : "KhronosGroup/SPIRV-Headers",
       "subdir" : "External/spirv-tools/external/spirv-headers",
-      "commit" : "111a25e4ae45e2b4d7c18415e1d6884712b958c4"
+      "commit" : "2434b89345a50c018c84f42a310b0fad4f3fd94f"
     }
   ]
 }