Panic in Compile

[mrduncan]

I found this interesting case during some fuzzing:

package main

import (
	"github.com/dop251/goja"
)

func main() {
	goja.Compile("", "({!:0})", false)
}

panic: runtime error: invalid memory address or nil pointer dereference [recovered]
	panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x30 pc=0x1227f5b]

goroutine 1 [running]:
github.com/dop251/goja.compileAST.func1()
	/Users/matt/go/pkg/mod/github.com/dop251/goja@v0.0.0-20211207134806-acd374ca9c94/runtime.go:1305 +0xb4
panic({0x133e160, 0x1797320})
	/usr/local/Cellar/go/1.17.3/libexec/src/runtime/panic.go:1038 +0x215
github.com/dop251/goja.(*compiledObjectLiteral).emitGetter(0xc00000c330, 0x1)
	/Users/matt/go/pkg/mod/github.com/dop251/goja@v0.0.0-20211207134806-acd374ca9c94/compiler_expr.go:1790 +0x45b
github.com/dop251/goja.(*compiler).compileExpressionStatement(0xc00006e510, 0x1012fa5, 0x1)
	/Users/matt/go/pkg/mod/github.com/dop251/goja@v0.0.0-20211207134806-acd374ca9c94/compiler_stmt.go:965 +0x83
github.com/dop251/goja.(*compiler).compileStatement(0x203000, {0x13f8f88, 0xc00001e4e0}, 0x10)
	/Users/matt/go/pkg/mod/github.com/dop251/goja@v0.0.0-20211207134806-acd374ca9c94/compiler_stmt.go:18 +0x413
github.com/dop251/goja.(*compiler).compileStatementsNeedResult(0x17a2f80, {0xc00001e4f0, 0x1, 0x1}, 0x0)
	/Users/matt/go/pkg/mod/github.com/dop251/goja@v0.0.0-20211207134806-acd374ca9c94/compiler_stmt.go:883 +0x1bf
github.com/dop251/goja.(*compiler).compileStatements(0xc00006e510, {0xc00001e4f0, 0x1, 0x1}, 0x1)
	/Users/matt/go/pkg/mod/github.com/dop251/goja@v0.0.0-20211207134806-acd374ca9c94/compiler_stmt.go:910 +0x7b
github.com/dop251/goja.(*compiler).compile(0xc00006e510, 0xc00007c1c0, 0x0, 0x0, 0x1)
	/Users/matt/go/pkg/mod/github.com/dop251/goja@v0.0.0-20211207134806-acd374ca9c94/compiler.go:748 +0xbca
github.com/dop251/goja.compileAST(0x0, 0x0, 0x0, 0x0)
	/Users/matt/go/pkg/mod/github.com/dop251/goja@v0.0.0-20211207134806-acd374ca9c94/runtime.go:1310 +0x107
github.com/dop251/goja.compile({0x0, 0x0}, {0x138ad3e, 0x1326200}, 0xa0, 0x1, 0x0, {0x0, 0x0, 0x0})
	/Users/matt/go/pkg/mod/github.com/dop251/goja@v0.0.0-20211207134806-acd374ca9c94/runtime.go:1292 +0x6a
github.com/dop251/goja.Compile(...)
	/Users/matt/go/pkg/mod/github.com/dop251/goja@v0.0.0-20211207134806-acd374ca9c94/runtime.go:1243
main.main()
	/Users/matt/code/scratch/main.go:8 +0x45
exit status 2