Make wat test export memory as well

While it's a bit redundant to both import and export a memory,
it's what WASI implementations expect.

Emscripten, toywasm:
Import alone is fine. But export wouldn't hurt.

wasm-micro-runtime:
Export is checked. Nothing actually seems to rely on it though.

wasmtime:
Export is necessary?

References:
https://github.com/WebAssembly/WASI/blob/main/legacy/application-abi.md#current-unstable-abi
WebAssembly#22

Author: yamt

test/testsuite/wasi_threads_exit_main_block.wat

@@ -1,5 +1,5 @@
 (module
-  (memory (import "foo" "bar") 1 1 shared)
+  (memory (export "memory") (import "foo" "bar") 1 1 shared)
   (func $thread_spawn (import "wasi" "thread_spawn") (param i32) (result i32))
   (func $proc_exit (import "wasi_snapshot_preview1" "proc_exit") (param i32))
   (func (export "wasi_thread_start") (param i32 i32)

test/testsuite/wasi_threads_exit_main_busy.wat

@@ -1,5 +1,5 @@
 (module
-  (memory (import "foo" "bar") 1 1 shared)
+  (memory (export "memory") (import "foo" "bar") 1 1 shared)
   (func $thread_spawn (import "wasi" "thread_spawn") (param i32) (result i32))
   (func $proc_exit (import "wasi_snapshot_preview1" "proc_exit") (param i32))
   (func (export "wasi_thread_start") (param i32 i32)

test/testsuite/wasi_threads_exit_main_wasi.wat

@@ -1,5 +1,5 @@
 (module
-  (memory (import "foo" "bar") 1 1 shared)
+  (memory (export "memory") (import "foo" "bar") 1 1 shared)
   (func $thread_spawn (import "wasi" "thread_spawn") (param i32) (result i32))
   (func $proc_exit (import "wasi_snapshot_preview1" "proc_exit") (param i32))
   (func $poll_oneoff (import "wasi_snapshot_preview1" "poll_oneoff") (param i32 i32 i32 i32) (result i32))

test/testsuite/wasi_threads_exit_nonmain_block.wat

@@ -1,5 +1,5 @@
 (module
-  (memory (import "foo" "bar") 1 1 shared)
+  (memory (export "memory") (import "foo" "bar") 1 1 shared)
   (func $thread_spawn (import "wasi" "thread_spawn") (param i32) (result i32))
   (func $proc_exit (import "wasi_snapshot_preview1" "proc_exit") (param i32))
   (func (export "wasi_thread_start") (param i32 i32)

test/testsuite/wasi_threads_exit_nonmain_busy.wat

@@ -1,5 +1,5 @@
 (module
-  (memory (import "foo" "bar") 1 1 shared)
+  (memory (export "memory") (import "foo" "bar") 1 1 shared)
   (func $thread_spawn (import "wasi" "thread_spawn") (param i32) (result i32))
   (func $proc_exit (import "wasi_snapshot_preview1" "proc_exit") (param i32))
   (func (export "wasi_thread_start") (param i32 i32)

test/testsuite/wasi_threads_exit_nonmain_wasi.wat

@@ -1,5 +1,5 @@
 (module
-  (memory (import "foo" "bar") 1 1 shared)
+  (memory (export "memory") (import "foo" "bar") 1 1 shared)
   (func $thread_spawn (import "wasi" "thread_spawn") (param i32) (result i32))
   (func $proc_exit (import "wasi_snapshot_preview1" "proc_exit") (param i32))
   (func $poll_oneoff (import "wasi_snapshot_preview1" "poll_oneoff") (param i32 i32 i32 i32) (result i32))

test/testsuite/wasi_threads_spawn.wat

@@ -1,5 +1,5 @@
 (module
-  (memory (import "foo" "bar") 1 1 shared)
+  (memory (export "memory") (import "foo" "bar") 1 1 shared)
   (func $thread_spawn (import "wasi" "thread_spawn") (param i32) (result i32))
   (func $proc_exit (import "wasi_snapshot_preview1" "proc_exit") (param i32))
   (func (export "wasi_thread_start") (param i32 i32)