On architectures where we don't have any special inline code for

On architectures where we don't have any special inline code for
GCC, the inner "#if defined(__GNUC__)" can just be omitted in that
architecture's block.

The existing arrangement with an outer "#if defined(__GNUC__)"
doesn't have any obvious benefit, and it encourages missed cases
like this one.

BTW, I'd suggest making the definition of clear_lock for HPUX be

static const slock_t clear_lock = {{-1, -1, -1, -1}};

The extra braces are needed to suppress warnings from gcc, and
declaring it const just seems like good practice.

			regards, tom lane