fuzz: Adjust where NaN canonicalization is configured

Behavior of Winch changed in bytecodealliance#12939 in such a way that it's breaking
differential fuzz testing with wasmi. Now that Winch supports NaN
canonicalization this commit adjusts the fuzz test configuration
generation to additionally enable it for Winch in addition to Cranelift.

Author: alexcrichton

crates/fuzzing/src/generators/config.rs

@@ -334,6 +334,11 @@ impl Config {
 
         cfg.codegen.inlining = self.wasmtime.inlining;
 
+        // If the wasm-smith-generated module use nan canonicalization then we
+        // don't need to enable it, but if it doesn't enable it already then we
+        // enable this codegen option.
+        cfg.wasm.nan_canonicalization = Some(!self.module_config.config.canonicalize_nans);
+
         // Only set cranelift specific flags when the Cranelift strategy is
         // chosen.
         if cranelift_strategy {
@@ -358,11 +363,6 @@ impl Config {
                 ));
             }
 
-            // If the wasm-smith-generated module use nan canonicalization then we
-            // don't need to enable it, but if it doesn't enable it already then we
-            // enable this codegen option.
-            cfg.wasm.nan_canonicalization = Some(!self.module_config.config.canonicalize_nans);
-
             // Enabling the verifier will at-least-double compilation time, which
             // with a 20-30x slowdown in fuzzing can cause issues related to
             // timeouts. If generated modules can have more than a small handful of