Hi 👋 and thanks for the super-helpful project!

On my Mac I ca reproduce as follows (in a tmp folder):

```bash
git clone https://github.com/WebAssembly/testsuite.git
wget https://github.com/WebAssembly/wabt/releases/download/1.0.34/wabt-1.0.34-macos-12.tar.gz
./wabt-1.0.34/bin/wast2json ./testsuite/if.wast
```

Produces the unexpected result:

```bash
./testsuite/if.wast:533:33: error: unexpected token (, expected ).
    (if (i32.const 1) (i32.eqz) (then) (else))
                                ^
./testsuite/if.wast:537:17: error: unexpected token "invoke", expected an instr.
(assert_return (invoke "empty" (i32.const 0)))
                ^^^^^^
```

The regression seems to be caused by this diff:
https://github.com/WebAssembly/testsuite/commit/26d62d0ad297b14218807cd20d9b568e11ec7bd9#diff-76c78c41ca3eaa954f864741d9462243de307c6e0ca747b7bcab93fba9767837

`wast2json` fails to parse `if.wast` from latest testsuite
This is a GitHub Issue
repo:wabt
owner:WebAssembly
Title : `wast2json` fails to parse `if.wast` from latest testsuite
Issue date:

--- start body ---
Hi 👋 and thanks for the super-helpful project!

On my Mac I ca reproduce as follows (in a tmp folder):

```bash
git clone https://github.com/WebAssembly/testsuite.git
wget https://github.com/WebAssembly/wabt/releases/download/1.0.34/wabt-1.0.34-macos-12.tar.gz
./wabt-1.0.34/bin/wast2json ./testsuite/if.wast
```

Produces the unexpected result:

```bash
./testsuite/if.wast:533:33: error: unexpected token (, expected ).
    (if (i32.const 1) (i32.eqz) (then) (else))
                                ^
./testsuite/if.wast:537:17: error: unexpected token "invoke", expected an instr.
(assert_return (invoke "empty" (i32.const 0)))
                ^^^^^^
```

The regression seems to be caused by this diff:
https://github.com/WebAssembly/testsuite/commit/26d62d0ad297b14218807cd20d9b568e11ec7bd9#diff-76c78c41ca3eaa954f864741d9462243de307c6e0ca747b7bcab93fba9767837

--- end body ---
