Set CMAKE_LIBRARY_ARCHITECTURE to amd64 by default for 64bit This pre…

…vents cmake from picking up the 32bit version when compiling for 64bit.

To test make a CMakeLists.txt:

find_library(XTEST X11)
message("Found X11 at ${XTEST}")

And compile with :

cmake .
rm CMakeCache.txt
cmake -DCMAKE_LIBRARY_ARCHITECTURE=amd64 .

make-rules/cmake.mk

@@ -149,6 +149,7 @@ CMAKE_OPTIONS += -DLIBEXEC_INSTALL_DIR="$(CMAKE_PREFIX)/$(CMAKE_LIBEXECDIR.$(BIT
 # variable that we can generally use to accomplish the same result.  Setting
 # them both shouldn't harm anything.
 CMAKE_OPTIONS += -DLIB_INSTALL_DIR="$(CMAKE_PREFIX)/$(CMAKE_LIBDIR.$(BITS))"
+CMAKE_OPTIONS.64 += -DCMAKE_LIBRARY_ARCHITECTURE=amd64
 CMAKE_OPTIONS.64 += -DLIB_SUFFIX="/$(MACH64)"
 endif
 CMAKE_OPTIONS += $(CMAKE_OPTIONS.$(BITS))