[BUG] - crash on c++ exception when importing 2 pybind submodules built from different MSVC versions

Issue description

Update: After diving deep in the pybind11 comments inside the code (Thanks God for it!) I am rephrasing the issue.

It looks like different MSVC versions that build modules with pybind11 interfere with each other (due to use of common resources between python modules).
The PYBIND11_INTERNALS_ID string is not constructed from a _MSC_VER and when I miss match modules build with MSVC 14.0
and MSVC >= 14.2 the ID is the same and I get a crash

Here is the crash stack

The "registered_exception_translators" list is not empty, but once you try to access the translator you get access violation.

I saw the "PYBIND11_COMPILER_TYPE" definition can be override,
I guess what I see here is that mismatch between MSVC versions also cause problems and perhaps should be considered as a different ABI.

Question:
What are the benefits of using the same "Internals" between modules? is it memory consumption?
It seems like if I force override the ABI version it works (add_definitions(-DPYBIND11_COMPILER_TYPE="_testing")

This is my workaround for now, I can suggest a PR that integrate MSC version as part of the ABI_ID..

Thanks

Thanks
Nir

Start by tracing PYBIND11_INTERNALS_ID, PYBIND11_COMPILER_TYPE, and the registered_exception_translators list in the pybind11 implementation; no file or test is named in the issue. Reproduce imports of submodules built with MSVC 14.0 and MSVC >= 14.2, then establish whether the ABI identity must distinguish these compiler versions and verify that exception translation no longer crashes.