Folding in base, integer-{gmp, single}, ghc-prim, and haskell-template into ghc.git

[Kazu Yamamoto (=?iso-2022-jp?B?GyRCOzNLXE9CSScbKEI=?=)]

Hi Herbert,

> After a short conversion with Austin and Edward it appears that the
> sensible course of action with respect towards moving to a proper Git
> submodule set-up is to fold-in the 5 Git repos listed below (which btw
> are all GHC wired-in packages) directly into ghc.git (the same way
> testsuite.git was a few months ago):

This is just a confirmation. I have no opinion on this.

Recalling the discussion in the last summer, I understood GHC project
will start using git subtree, not git submodule. But it seems to me
this is my misunderstanding.

What was the conclusion of that discussion? And would you tell me why
submodule was chosen?

--Kazu