Wrong rewriting of extern function pointer with itype

[mattmccutchen-cci]

On the following input:

extern _Ptr<char *(void) : itype(_Ptr<char>)> fp1;
_Ptr<char *(void) : itype(_Ptr<char>)> fp2;

3c with no options gives this syntactically invalid output:

extern _Ptr<char *(void)> fp1<char *(void) : itype(_Ptr<char>)> fp1;
_Ptr<char *(void) : itype(_Ptr<char>)> fp2;

So the extern variable was changed and the non-extern variable wasn't. That's the opposite of what I might expect.

I discovered this bug in the process of reducing a test case for a different bug that appeared on Windows. AFAIK this bug itself is not yet affecting the regression tests on either Linux or Windows.