Auto merge of #2491 - devnexen:solarish_sendfile, r=JohnTitor

sendfile fn for solarish systems

Author: bors

src/unix/solarish/mod.rs

@@ -2772,6 +2772,9 @@ extern "C" {
 
     pub fn getpflags(flags: ::c_uint) -> ::c_uint;
     pub fn setpflags(flags: ::c_uint, value: ::c_uint) -> ::c_int;
+
+    pub fn sendfile(out_fd: ::c_int, in_fd: ::c_int, off: *mut ::off_t, len: ::size_t)
+        -> ::ssize_t;
 }
 
 mod compat;