[cmake] Pass CMAKE_MAKE_PROGRAM to native configure
If the make program isn't in the path, the native configure will fail.
Pass CMAKE_MAKE_PROGRAM to the native configure explicitly to remedy
this, similar to what's already done for external project configuration.
Explicitly set CMAKE_MAKE_PROGRAM before the user flags so that they can
override it for the native build if they desire (though I can't fathom
why that would be useful).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322032
91177308-0d34-0410-b5e6-
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