...as GCC 4.6 reports "error: invalid cast from type 'pthread_t {aka long
unsigned int}' to type 'long unsigned int'" despite [expr.reinterpret.cast]/2:
"An expression of integral, enumeration, pointer, or pointer-to-member type can
be explicitly converted to its own type; such a cast yields the value of its
operand."

Change-Id: I26f1a3e6df2f0e55c665ad4f49185e0ebf432e95