Typedefs don't work at function scope and cause confusing errors

[blickly]

This issue was imported from Closure Compiler's previous home at http://closure-compiler.googlecode.com

The original discussion is archived at:
http://blickly.github.io/closure-compiler-issues/#1026

[sinelaw]

+1

[concavelenz]

The new type inference fixes this problem. We are unlikely to fix it in the current type inference.

[dimvar]

Removing the NTI label since this works correctly there. Downgrading to P3 for the current type checker.