Declarations after statements in front ends

[Richard Kenner]

    There's generally no good reason to use GNU C extensions in non-C
    front ends, though, and enforcing a consistent coding style across the
    entire compiler makes life simpler for everyone.  Also, it can be
    convenient during development to build everything with whatever
    compiler you've got lying around.

And indeed the C parts of the Ada front end are coded in exactly the
same style as the middle-end.  No GNU C extensions are intentionally used,
though it's always possible some have snuck in since I don't think
anybody's tried to compile it with extensions turned off.