test: Enable rust-lang#9205-related tests on windows

Fixes rust-lang#9205.

Author: klutzy

src/test/run-pass/extern-pass-TwoU64s.rs

@@ -11,8 +11,6 @@
 // Test a foreign function that accepts and returns a struct
 // by value.
 
-// ignore-win32 #9205
-
 #[deriving(PartialEq, Show)]
 struct TwoU64s {
     one: u64, two: u64

src/test/run-pass/extern-return-TwoU64s.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// ignore-win32 #9205
-
 struct TwoU64s {
     one: u64, two: u64
 }

src/test/run-pass/struct-return.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// ignore-win32 #9205
-
 pub struct Quad { a: u64, b: u64, c: u64, d: u64 }
 pub struct Floats { a: f64, b: u8, c: f64 }