Hi,

This patch merges the D front-end implementation with dmd upstream 237ca3fbe.

Backports a fix where a bad cast to TypeFunction resulted in memory
corruption.  The logic in the function semantic has been fixed, and
casts have been replaced with a function call to always check the
front-end AST node value.

Bootstrapped and tested on x86_64-linux-gnu.

Committed to trunk as r267207.

-- 
Iain
---