Add tests for rust-lang#113

resolves rust-lang#113

Author: oli-obk

tests/compile-fail/transmute_fat.rs

@@ -0,0 +1,13 @@
+#![feature(i128_type)]
+
+fn main() {
+    #[cfg(target_pointer_width="64")]
+    let bad = unsafe {
+        std::mem::transmute::<&[u8], u128>(&[1u8])
+    };
+    #[cfg(target_pointer_width="32")]
+    let bad = unsafe {
+        std::mem::transmute::<&[u8], u64>(&[1u8])
+    };
+    bad + 1; //~ ERROR a raw memory access tried to access part of a pointer value as raw bytes
+}

tests/compile-fail/transmute_fat2.rs

@@ -0,0 +1,13 @@
+#![feature(i128_type)]
+
+fn main() {
+    #[cfg(target_pointer_width="64")]
+    let bad = unsafe {
+        std::mem::transmute::<u128, &[u8]>(42)
+    };
+    #[cfg(target_pointer_width="32")]
+    let bad = unsafe {
+        std::mem::transmute::<u64, &[u8]>(42)
+    };
+    bad[0]; //~ ERROR index out of bounds: the len is 0 but the index is 0
+}