Compiler changes:
* Change map assignment to use mapassign and assign value directly.
* Change string iteration to use decoderune, faster for ASCII strings.
* Change makeslice to take int, and use makeslice64 for larger values.
* Add new noverflow field to hmap struct used for maps.
Unresolved problems, to be fixed later:
* Commented out test in go/types/sizes_test.go that doesn't compile.
* Commented out reflect.TestStructOf test for padding after zero-sized field.
Reviewed-on: https://go-review.googlesource.com/35231
gotools/:
Updates for Go 1.8rc1.
* Makefile.am (go_cmd_go_files): Add bug.go.
(s-zdefaultcc): Write defaultPkgConfig.
* Makefile.in: Rebuild.
From-SVN: r244456
Only build net/hook_cloexec.go on GNU/Linux and FreeBSD, because those
are the only systems with accept4.
Add syscall/libcall_bsd.go to define sendfile for *BSD and Solaris.
Revert tcpsockopt_solaris.go back to the earlier version, so that it
works on Solaris 10.
Always pass the address of a Pid_t value to TIOCGPGRP and TIOCSPGRP.
Include <unistd.h> in runtime/go-varargs.c.
Reviewed-on: https://go-review.googlesource.com/16719
From-SVN: r229880
Calls to library functions now use entersyscall and
exitsyscall as appropriate. This is a first step toward
multiplexing goroutines onto threads.
From-SVN: r180345
