Numpy will not build if this is not set because it
has code that follows the c99 standard. icc is set to c89 by
default. Look below at IntelCCompilerW which is the icc equivalent
on Windows and that one already has c99 set.

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

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.

behavior affect at least python 3.5 and SciPy build and build failed.
During initialization <python>.distutils.MSVCCompiler replace Intel
environment('include' and 'lib' paths). This fix decorate 'initialize'
function in MSVCCompiler and extend 'lib' and 'include' environment
variables. Changed compilation keys: generate optimized code
specialized for Intel processors with SSE4.2 support.