* cygheap.cc (cygheap_fixup_in_child): Drop call to set_dll_dir.
(init_cygheap::init_installation_root): Set installation_dir_len.
(setup_cygheap): Drop call to set_dll_dir.
* cygheap.h (struct init_cygheap): Add installation_dir_len member.
(init_cygheap::set_dll_dir): Remove.
* environ.cc (win_env::add_cache): Use stpcpy for speed.
(posify_maybe): Use tmp_pathbuf buffer instead of stack.
(raise_envblock): New function to resize Windows environment block.
(build_env): Fix indentation. Call raise_envblock function. Check if
$PATH exists and is non-empty. If not, add PATH variable with Cygwin
installation directory as content to Windows environment. Explain why.
* uinfo.cc (cygheap_pwdgrp::_nss_init): Fill UNICODE_STRING members
on the fly. Drop call to RtlInitUnicodeString.
(pwdgrp::check_file): Ditto.