Make target pointer-width specific variants of (very old) huge-array-simple.rs test.

(and now unignore the test since it shouldn't break tests of
cross-compiles anymore.)

src/test/ui/huge-array-simple.rs

@@ -1,11 +1,16 @@
-// FIXME (#23926): the error output is not consistent between a
-// self-hosted and a cross-compiled setup. Skipping for now.
-
-// ignore-test FIXME(#23926)
+// error-pattern: too big for the current architecture
 
+// normalize-stderr-test "; \d+]" -> "; N]"
 #![allow(exceeding_bitshifts)]
 
+#[cfg(target_pointer_width = "64")]
 fn main() {
     let _fat : [u8; (1<<61)+(1<<31)] =
         [0; (1u64<<61) as usize +(1u64<<31) as usize];
 }
+
+#[cfg(target_pointer_width = "32")]
+fn main() {
+    let _fat : [u8; (1<<31)+(1<<15)] =
+        [0; (1u32<<31) as usize +(1u32<<15) as usize];
+}

src/test/ui/huge-array-simple.stderr

@@ -0,0 +1,4 @@
+error: the type `[u8; N]` is too big for the current architecture
+
+error: aborting due to previous error
+