Cannot fork() javascript files when run with 'coffee' command

[ashtuchkin]

# index.coffee
{fork} = require "child_process"

fork("child.js")

// child.js
var a = 0;

$ coffee index.coffee
SyntaxError: In child.js, reserved word "var" on line 1
    at SyntaxError (unknown source)
    at Lexer.exports.Lexer.Lexer.error (/home/ubuntu/testrequire/node_modules/coffee-script/lib/coffee-script/lexer.js:682:13)
    ...

The error message comes from the child process, which is exec-ed as coffee child.js.

Seems that the problem is in process.execPath, see:
https://github.com/joyent/node/blob/master/lib/child_process.js#L444
https://github.com/jashkenas/coffee-script/blob/master/src/command.coffee#L79

So, in current state, it is impossible to fork javascript modules when using coffee command.

Seems that it's also related to #1303

Context: From a coffeescript project, I'm require-ing a javascript module that forks a new node process and knows nothing about coffee.

[jashkenas]

I don't really see why we should be resetting process.execPath ... so I'll remove that line, which should fix your problem.

@TrevorBurnham -- let me know if there was a good reason why it's there.

[ashtuchkin]

Confirmed the fix. Thanks!