libstdc++: Add always_inline to trivial range access functions

This makes all the [iterator.range] functions always-inline, except the
ones that construct a std::reverse_iterator, as they do a little more
work. They could probably be made always_inline too though, and maybe
the std::reverse_iterator constructor too.

This means that even for -O0 these functions have no runtime overhead
compared with calling a member of the container, or performing pointer
arithmetic for arrays.

libstdc++-v3/ChangeLog:

	* include/bits/range_access.h: Add always_inline attribute to
	trivial functions.
1 file changed