only e3sm has the unique sharedlib setup

[jgfouca]

This should fix #3427

Test suite: None
Test baseline:
Test namelist changes:
Test status: [bit for bit, roundoff, climate changing]

Fixes [CIME Github issue #]

User interface changes?:

Update gh-pages html (Y/N)?:

Code review:

[jgfouca]

@jedwards4b , this raises a broader issue. Now that we have more models, the following:

if get_model() == "cesm"

and

if get_model() != "e3sm"

Are no longer semantically equivalent. We probably need to do a quick review of the repo to make sure we are being consistent.

[rljacob]

Why does e3sm do shared libs that way? Can we switch back?

We should have a separate issue for use of get_model = throughout the code.

[jgfouca]

@rljacob , I can't even remember; I made the change years ago because something was broken. It's on my todo-list to re-evaluate.