rand_xorshift: fix Endianness in from_rng

Author: dhardy

rand_xorshift/CHANGELOG.md

@@ -6,6 +6,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [0.1.2] - 2019-06-06
 - Bump `rand_core` version
+- Make XorShiftRng::from_rng portable by enforcing Endianness (#815)
 
 ## [0.1.1] - 2019-01-04
 - Reorganise code and tests; tweak doc

rand_xorshift/src/lib.rs

@@ -110,6 +110,10 @@ impl SeedableRng for XorShiftRng {
                 let slice = slice::from_raw_parts_mut(ptr, 4 * 4);
                 rng.try_fill_bytes(slice)?;
             }
+            for v in seed_u32.iter_mut() {
+                // enforce LE for consistency across platforms
+                *v = v.to_le();
+            }
             if !seed_u32.iter().all(|&x| x == 0) { break; }
         }