Hello I have an issue when running global.json generated from global.wast, for example global.json starts like this:

```json
{"source_filename": ".../wasm-testsuite/global.wast",
 "commands": [
  {"type": "module", "line": 3, "filename": "global.0.wasm"}, 
  {"type": "assert_return", "line": 196, "action": {"type": "invoke", "field": "get-a", "args": []}, "expected": [{"type": "i32", "value": "4294967294"}]}, 
```

So you can see the instantiate module is the first command with none prior, however global.0.wasm has an import:

```wat
 wasm2wat global.0.wasm 
(module
  (type (;0;) (func (param i32 i32) (result i32)))
  (type (;1;) (func (result i32)))
  (type (;2;) (func (result i64)))
  (type (;3;) (func (result externref)))
  (type (;4;) (func (param i32)))
  (type (;5;) (func (param i64)))
  (type (;6;) (func (param externref)))
  (type (;7;) (func (result f32)))
  (type (;8;) (func (result f64)))
  (type (;9;) (func (param f32)))
  (type (;10;) (func (param f64)))
  (type (;11;) (func))
  (type (;12;) (func (param i32) (result i32)))
  (import "spectest" "global_i32" (global (;0;) i32))
```

If this is the first command in the script how could an import be resolved? Unless a module is instantiable with missing imports? 🤔 
Missing Import when running global.wast
This is a GitHub Issue
repo:wabt
owner:WebAssembly
Title : Missing Import when running global.wast
Issue date:

--- start body ---
Hello I have an issue when running global.json generated from global.wast, for example global.json starts like this:

```json
{"source_filename": ".../wasm-testsuite/global.wast",
 "commands": [
  {"type": "module", "line": 3, "filename": "global.0.wasm"}, 
  {"type": "assert_return", "line": 196, "action": {"type": "invoke", "field": "get-a", "args": []}, "expected": [{"type": "i32", "value": "4294967294"}]}, 
```

So you can see the instantiate module is the first command with none prior, however global.0.wasm has an import:

```wat
 wasm2wat global.0.wasm 
(module
  (type (;0;) (func (param i32 i32) (result i32)))
  (type (;1;) (func (result i32)))
  (type (;2;) (func (result i64)))
  (type (;3;) (func (result externref)))
  (type (;4;) (func (param i32)))
  (type (;5;) (func (param i64)))
  (type (;6;) (func (param externref)))
  (type (;7;) (func (result f32)))
  (type (;8;) (func (result f64)))
  (type (;9;) (func (param f32)))
  (type (;10;) (func (param f64)))
  (type (;11;) (func))
  (type (;12;) (func (param i32) (result i32)))
  (import "spectest" "global_i32" (global (;0;) i32))
```

If this is the first command in the script how could an import be resolved? Unless a module is instantiable with missing imports? 🤔 
--- end body ---
