It's very unlikely that `ifort` is supposed to be invoked as `ifort "-fpmodel strict"` instead of `ifort -fpmodel strict` .

Spaces in flag items will end up passed as a single argument.

As numpy is Python 3 only, these import statements are now unnecessary
and don't alter runtime behavior.

After the recent patch to CCompiler.spawn, the file-paths no longer need manual quoting - that's handled as needed within subprocess.

This also states our assumption that our paths do not contain commas.
If we care about this, we could adopt the approach used by https://github.com/rust-lang/rust/issues/38795.

Tested for gcc locally by looking at the error messages of `subprocess.check_call(["gcc", r'-Wl,spaces and no quotes'])`

Other fortran compiler changes not tested, but assumed to be broken in the same way.

Fixes #12882

Note that this was discussed extensively in gh-7287, but removing
this -xhost flag was missed in the PR that closed that issue.

Fixes two problems:

* c compilers do not have a find_executables method.
* get_version return a LooseVersion instance, not string.

Closes #9278.

[ci skip]

The '-openmp' option was deprecated in Intel version 15 and removed
in version 18. The replacement is '-qopenmp'.

Closes #8941.

[skip ci]

In Python 3.6 a number of escape sequences that were previously accepted
-- for instance "\(" that was translated to "\\(" -- are deprecated. To
retain the previous behavior either raw strings must be used or the
backslash must be properly escaped itself.

The consensus seems to be that hardcoding SSE4.2 results in poor code
for architectures lacking the feature.

Closes #7287.