[tint][fuzzers] Apply SubstituteOverrides to ir roundtrip fuzzer

IR doesn't handle overrides

Change-Id: Idba86dc09f32f467aca18a1e94f4665bf17518c6
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/140983
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: James Price <jrprice@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Commit-Queue: Ben Clayton <bclayton@google.com>
Auto-Submit: Ben Clayton <bclayton@google.com>
diff --git a/src/tint/fuzzers/tint_ir_roundtrip_fuzzer.cc b/src/tint/fuzzers/tint_ir_roundtrip_fuzzer.cc
index 0ec7710..438ec91 100644
--- a/src/tint/fuzzers/tint_ir_roundtrip_fuzzer.cc
+++ b/src/tint/fuzzers/tint_ir_roundtrip_fuzzer.cc
@@ -16,6 +16,7 @@
 #include <string>
 #include <unordered_set>
 
+#include "src/tint/fuzzers/apply_substitute_overrides.h"
 #include "src/tint/ir/from_program.h"
 #include "src/tint/ir/to_program.h"
 #include "src/tint/reader/wgsl/parser_impl.h"
@@ -45,6 +46,11 @@
         return 0;
     }
 
+    src = tint::fuzzers::ApplySubstituteOverrides(std::move(src));
+    if (!src.IsValid()) {
+        return 0;
+    }
+
     auto ir = tint::ir::FromProgram(&src);
     if (!ir) {
         std::cerr << ir.Failure() << std::endl;