powerpc: add cdefs for linux

This borrowed entirely from the mips definitions, and should be
revisited after it lands while testing.

Author: richo

src/libstd/sys/unix/c.rs

@@ -33,7 +33,9 @@ pub const FIONBIO: libc::c_ulong = 0x8004667e;
           target_os = "android"))]
 pub const FIONBIO: libc::c_ulong = 0x5421;
 #[cfg(all(target_os = "linux",
-          any(target_arch = "mips", target_arch = "mipsel")))]
+          any(target_arch = "mips",
+              target_arch = "mipsel",
+              target_arch = "powerpc")))]
 pub const FIONBIO: libc::c_ulong = 0x667e;
 
 #[cfg(any(target_os = "macos",
@@ -49,7 +51,9 @@ pub const FIOCLEX: libc::c_ulong = 0x20006601;
           target_os = "android"))]
 pub const FIOCLEX: libc::c_ulong = 0x5451;
 #[cfg(all(target_os = "linux",
-          any(target_arch = "mips", target_arch = "mipsel")))]
+          any(target_arch = "mips",
+              target_arch = "mipsel",
+              target_arch = "powerpc")))]
 pub const FIOCLEX: libc::c_ulong = 0x6601;
 
 #[cfg(any(target_os = "macos",
@@ -182,7 +186,9 @@ mod signal {
 }
 
 #[cfg(all(target_os = "linux",
-          any(target_arch = "mips", target_arch = "mipsel")))]
+          any(target_arch = "mips",
+              target_arch = "mipsel",
+              target_arch = "powerpc")))]
 mod signal {
     use libc;