Fix typeid(real).getHash() on 32-bit x86

Where real.sizeof is 12, not 16, and so the 2 padding bytes weren't
ignored.

Fixes the rt.util.typeinfo unittests (only failing when testing the 32-bit
shared runtime unittests, which we don't in CI).

src/rt/util/typeinfo.d

@@ -7,7 +7,7 @@
  */
 module rt.util.typeinfo;
 
-private enum isX87Real(T) = (T.sizeof == 16 && T.mant_dig == 64 && T.max_exp == 16384);
+private enum isX87Real(T) = (T.mant_dig == 64 && T.max_exp == 16384);
 
 template Floating(T)
 if (is(T == float) || is(T == double) || is(T == real))