Exact OpenBSD semantics: strlcpy returns strlen(src) and writes at most
size-1 bytes plus NUL; strlcat returns dlen + strlen(src) with
dlen = min(size, strlen(dst)) and never reads past size bytes in dst.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <[email protected]>
Word-at-a-time memcpy/memmove/memset/strlen/strcmp implementing the
level-1 string slice. memcpy carries an optimize(no-tree-loop-
distribute-patterns) attribute: GCC's loop-distribution pass rewrites
its word-copy loop into a self-recursive memcpy@plt call at -O2/-O3
otherwise.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <[email protected]>
Gate the initial string slice per compatibility level: L1 sources compile
everywhere, strlcpy/strlcat only at level >= 2 (PROFILE_GE_2), strcasestr
only at level >= 3 (PROFILE_GE_3). Install the generated
include/vlibc/features.h under $(vlibc_includedir)/vlibc/ via a dedicated
vlibc_featuresdir primary (nodist_nobase is rejected by automake and loses
the vlibc/ subpath). Include stddef.h/string.h in vlibc_include_HEADERS.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <[email protected]>
huntedbytheirsandSisyphus