preparation for exec.

* syscall:
	add syscall.RawSyscall, which doesn't use sys.entersyscall/sys.exitsyscall
	add syscall.dup2
	add syscall.BytePtrPtr
	add syscall.Rusage, RusagePtr
	add syscall.F_GETFD, F_SETFD, FD_CLOEXEC

* runtime:
	clean up, correct signal handling.
	can now survive (continue running after) a signal.

R=r
DELTA=394  (286 added, 51 deleted, 57 changed)
OCL=20351
CL=20369

1 files changed, 19 insertions, 0 deletions

diff --git a/test/sigchld.go b/test/sigchld.go
new file mode 100644
index 0000000000..417b833c70
--- /dev/null
+++ b/test/sigchld.go
@@ -0,0 +1,19 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "syscall"
+
+func getpid() int64 {
+	r1, r2, err := syscall.Syscall(syscall.SYS_GETPID, 0, 0, 0);
+	return r1;
+}
+
+func main() {
+	syscall.Syscall(syscall.SYS_KILL, getpid(), syscall.SIGCHLD, 0);
+	println("survived SIGCHLD");
+}