ConstantInteger32::shouldBeRandomizedOrPooled() was defined in a
source file and not resolvable. Move its definition inline.

BUG=swiftshader:7

Change-Id: I693ef93a9986e11b4e24f0194c9260f074567b81
Reviewed-on: https://chromium-review.googlesource.com/380422Reviewed-by: Jim Stichnoth <stichnot@chromium.org>
Tested-by: Nicolas Capens <nicolascapens@google.com>