fuzzgen: Unconditionally enable some flags

cranelift/fuzzgen/src/lib.rs

@@ -245,13 +245,9 @@ where
         //   aarch64: https://github.com/bytecodealliance/wasmtime/issues/2735
         let bool_settings = [
             "enable_alias_analysis",
-            "enable_simd",
-            "enable_float",
-            "enable_atomics",
             "enable_safepoints",
             "unwind_info",
             "preserve_frame_pointers",
-            "machine_code_cfg_info",
             "enable_jump_tables",
             "enable_heap_access_spectre_mitigation",
             "enable_table_access_spectre_mitigation",
@@ -283,6 +279,16 @@ where
         // This is the default, but we should ensure that it wasn't accidentally turned off anywhere.
         builder.enable("enable_verifier")?;
 
+        // These settings just panic when they're not enabled and we try to use their respective functionality
+        // so they aren't very interesting to be automatically generated.
+        builder.enable("enable_atomics")?;
+        builder.enable("enable_float")?;
+        builder.enable("enable_simd")?;
+
+        // `machine_code_cfg_info` generates additional metadata for the embedder but this doesn't feed back
+        // into compilation anywhere, we leave it on unconditionally to make sure the generation doesn't panic.
+        builder.enable("machine_code_cfg_info")?;
+
         Ok(Flags::new(builder))
     }