Bug: not checking if function exists when containing variables as part of the call.

[nihilus]

For bugs

• Rule Id (if any, e.g. SC1000):
• My shellcheck version ("0.4.7"):
• I tried on shellcheck.net and verified that this is still a problem on the latest commit
• It's not reproducible on shellcheck.net, but I think that's because it's an OS, configuration or encoding issue

Here's a snippet or screenshot that shows the problem:

#!/your/interpreter
foo(){
...
}

foo"$bar"

Here's what shellcheck currently says:

Nothing

Here's what I wanted or expected to see:

It should yield an error since eiether I want to call 'foo "$bar"' or 'foo$bar'.