Add powerpc to run-pass/conditional-compile-arch.rs

Author: malbarbo

src/test/run-pass/conditional-compile-arch.rs

@@ -28,6 +28,9 @@ pub fn main() { }
 #[cfg(target_arch = "mips64")]
 pub fn main() { }
 
+#[cfg(target_arch = "powerpc")]
+pub fn main() { }
+
 #[cfg(target_arch = "powerpc64")]
 pub fn main() { }