move rsyscall out of pthread_create module

this is something of a tradeoff, as now set*id() functions, rather
than pthread_create, are what pull in the code overhead for dealing
with linux's refusal to implement proper POSIX thread-vs-process
semantics. my motivations are:

1. it's cleaner this way, especially cleaner to optimize out the
rsyscall locking overhead from pthread_create when it's not needed.
2. it's expected that only a tiny number of core system programs will
ever use set*id() functions, whereas many programs may want to use
threads, and making thread overhead tiny is an incentive for "light"
programs to try threads.

1 files changed, 1 insertions, 2 deletions

diff --git a/src/unistd/setregid.c b/src/unistd/setregid.c
index ff2607dc..49c59858 100644
--- a/src/unistd/setregid.c
+++ b/src/unistd/setregid.c
@@ -4,6 +4,5 @@
 
 int setregid(gid_t rgid, gid_t egid)
 {
-	if (libc.rsyscall) return libc.rsyscall(__NR_setregid, rgid, egid, 0, 0, 0, 0);
-	return syscall(SYS_setregid, rgid, egid);
+	return __rsyscall(__NR_setregid, rgid, egid, 0, 0, 0, 0);
 }