devel/cdecl: upgrade to 6.11.

Added inline, restrict, and thread
Added GNU C's inline, restrict, and thread.

Added GNU C types
The GNU C types _Decimal32, _Decimal64, _Decimal128, _Float128, float128, _Float16, fp16, ibm128, _Float64x, float80, and __int128 were added to the set of predefined types.

Added WIN32 types
All of the Windows types, e.g., DWORD, HANDLE, INT, etc., given here were added to the set of predefined types.

Fixed retypedef
Fixed a crash caused by a case like:

typedef int I
typedef I J
typedef I J