[fuzz][ir] Set options when running non-concurrently

There are two execution paths in tint_ir_fuzzer, one for concurrent
execution and one for serial execution. Some of the options that are
set in the concurrent path are not set in the serial path.

This is just a spot fix for an issue that is causing problems right
now. There is a planned refactoring of the fuzzer implementations that
should more systematically address issues like this.

Bug: 506912899
Change-Id: Ic037d5018598a43fc2ac3c1345f3e6d3f659277a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/305655
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: dan sinclair <dsinclair@chromium.org>
Commit-Queue: dan sinclair <dsinclair@chromium.org>
Auto-Submit: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: James Price <jrprice@google.com>

Author: zoddicus

src/tint/cmd/fuzz/ir/fuzz.cc

@@ -205,6 +205,7 @@ void Run(const std::function<tint::core::ir::Module()>& acquire_module,
                 std::cout << " • Running: " << currently_running << '\n';
             }
             auto mod = acquire_module();
+            mod.dump_ir_when_validating = context.options.dump_ir_when_validating;
             if (tint::core::ir::Validate(mod, fuzzer.pre_capabilities,
                                          "start " + std::string(currently_running)) !=
                 tint::Success) {
@@ -217,6 +218,10 @@ void Run(const std::function<tint::core::ir::Module()>& acquire_module,
                 continue;
             }
 
+            // Enable validation assertions.
+            // Any validation failure after this point is a bug in Tint which we want to find.
+            mod.enable_validation_asserts = true;
+
             if (auto result = fuzzer.fn(mod, context, data); result != Success) {
                 if (options.verbose) {
                     std::cout << "   Failed to execute fuzzer: " << result.Failure() << "\n";