[Emit] Some import statements not emitted about typescript

[ahejlsberg]

The only difference I see is that the new compiler doesn't generate an (otherwise unused) local variable for an exported import statement. Specifically, given:

export import a = b;

the old compiler would generate:

var a = b;
exports.a = a;

where the new compiler simply generates:

exports.a = b;

Both compilers rewrite all references to a into exports.a so the new scheme definitely seems better.

from typescript.