debug/dmalloc: enforce cross-compilation

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Message-Id: <69772732f551aa342a2c.1363446264@laptop>
Patchwork-Id: 228221

 # windows config options

 ## depends on ARCH_x86

 ##

 ## select WINDOWS

 ##

 ## help Build a toolchain targeting systems running Windows as host