Remove provision of unnecessary fd rights (#2579)

The WASI docs allow for fewer rights to be applied to an fd than requested but
not more. This behavior is also asserted in the rust WASI tests, so it's necessary
for those to pass as well.

core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/posix.c

@@ -1981,20 +1981,6 @@ wasmtime_ssp_path_open(wasm_exec_env_t exec_env, struct fd_table *curfds,
         return error;
     }
 
-    {
-        struct stat sb;
-
-        if (fstat(nfd, &sb) < 0) {
-            close(nfd);
-            return convert_errno(errno);
-        }
-
-        if (S_ISDIR(sb.st_mode))
-            rights_base |= (__wasi_rights_t)RIGHTS_DIRECTORY_BASE;
-        else if (S_ISREG(sb.st_mode))
-            rights_base |= (__wasi_rights_t)RIGHTS_REGULAR_FILE_BASE;
-    }
-
     return fd_table_insert_fd(exec_env, curfds, nfd, type,
                               rights_base & max_base,
                               rights_inheriting & max_inheriting, fd);