* Add patch for Intel C++ compiler
- On some machines (in particular MacOSX Catalina), the icpc in some way
utilizes the preprocessor of the associated "developer tools" used by
icpc. This leads to, in some cases, a preprocessor claiming support for
__tuple_element_packs, even though icpc (as of version 21.1) can't
actually parse such code. Just use the MPARK_TUPLE_ELEMENT_PACK impl
with __icc until icpc supports it, to avoid issues with developer tools
that are untested.
- The same patch has been PRed against mpark-variant
9c139bf7a2