Fix Issue 11108 - `hasElaborateAssign` should check whether the type is assignable

Issue URL: http://d.puremagic.com/issues/show_bug.cgi?id=11108
std.process: Fix spawnProcess in Windows GUI programs (issue #11180)
Merge pull request #1618 from CyberShadow/std-process-gui-spawnprocess

std.process: Fix spawnProcess in Windows GUI programs (issue #11180)
Merge pull request #1598 from denis-sh/fix-Issue-11108

Fix Issue 11108 - `hasElaborateAssign` should check whether the type is assignable
Revert "Fix Issue 11108 - `hasElaborateAssign` should check whether the type is assignable"

This reverts commit e82724d740d223b52be2800eeec8d5ed4f673dfb.
Merge pull request #1621 from monarchdodra/undoHasElaborate

Revert "Fix Issue 11108 - `hasElaborateAssign` should check whether the ...