a small tweak to improve malloc in multithreaded programs. we don't need
to hold the malloc lock across mmap syscalls in all cases. dropping it
allows another thread to access the existing chunk cache if necessary.
could be improved to be a bit more aggressive, but i've been testing this
simple diff for some time now with good results.
remove return value from HOST_c2l/l2c macros

These macros and asm inlines simulate a function returning a value, but
nothing ever uses this return value. Remove the pseudo-returns and
(void) casts discarding the unused values.

This, maybe unsurprisingly, speeds things up a bit. It also removes the
GCC 4.9 warnings about unused values.

ok miod@ deraadt@
replace more ROTATE macros with plain-old C code.

Let the compiler optimize these. Even older versions of gcc generate
equal or better quality code than the inline asm.

ok miod@