[test] Fix typos (#1678)

Author: yamt

test/core/unreachable.wast

@@ -6,8 +6,8 @@
   (func $dummy3 (param i32 i32 i32))
 
   (func (export "type-i32") (result i32) (unreachable))
-  (func (export "type-i64") (result i32) (unreachable))
-  (func (export "type-f32") (result f64) (unreachable))
+  (func (export "type-i64") (result i64) (unreachable))
+  (func (export "type-f32") (result f32) (unreachable))
   (func (export "type-f64") (result f64) (unreachable))
 
   (func (export "as-func-first") (result i32)