Initial support for the ICL compiler on windows. Requires a new
c99wrap with ICL support (1.0.2+).

Currently not much different speed wise compared to msvc. In the
future with a few changes it can be made to support the inline asm.
This would be the primary reason for using it.

Passed all fate tests, versions tested:
    13.1.1.171 (2013 Update 3) x86 and x64
    12.1.5.344 (2011 Update 11) x86 and x64

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>