unsafe for cross-compilation

[Freed-Wu]

I got

$ cmake -Bbuild -DCMAKE_TOOLCHAIN_FILE=/usr/lib/cmake/xilinx/toolchain_clang_crosscomp_arm.cmake
...
    /opt/Xilinx/Vitis/2022.2/gnu/aarch64/lin/aarch64-linux/bin/../x86_64-petalinux-linux/usr/bin/aarch64-xilinx-linux/aarch64-xilinx-linux-ld.real: warning: library search path "/lib/../lib64" is unsafe for cross-compilation
    /opt/Xilinx/Vitis/2022.2/gnu/aarch64/lin/aarch64-linux/bin/../x86_64-petalinux-linux/usr/bin/aarch64-xilinx-linux/aarch64-xilinx-linux-ld.real: warning: library search path "/usr/lib/../lib64" is unsafe for cross-compilation
    /opt/Xilinx/Vitis/2022.2/gnu/aarch64/lin/aarch64-linux/bin/../x86_64-petalinux-linux/usr/bin/aarch64-xilinx-linux/aarch64-xilinx-linux-ld.real: warning: library search path "/lib" is unsafe for cross-compilation
    /opt/Xilinx/Vitis/2022.2/gnu/aarch64/lin/aarch64-linux/bin/../x86_64-petalinux-linux/usr/bin/aarch64-xilinx-linux/aarch64-xilinx-linux-ld.real: warning: library search path "/usr/lib" is unsafe for cross-compilation
    /opt/Xilinx/Vitis/2022.2/gnu/aarch64/lin/aarch64-linux/bin/../x86_64-petalinux-linux/usr/bin/aarch64-xilinx-linux/aarch64-xilinx-linux-ld.real: /lib/../lib64/Scrt1.o: Relocations in generic ELF (EM: 62)
    /opt/Xilinx/Vitis/2022.2/gnu/aarch64/lin/aarch64-linux/bin/../x86_64-petalinux-linux/usr/bin/aarch64-xilinx-linux/aarch64-xilinx-linux-ld.real: /lib/../lib64/Scrt1.o: Relocations in generic ELF (EM: 62)
    /opt/Xilinx/Vitis/2022.2/gnu/aarch64/lin/aarch64-linux/bin/../x86_64-petalinux-linux/usr/bin/aarch64-xilinx-linux/aarch64-xilinx-linux-ld.real: /lib/../lib64/Scrt1.o: error adding symbols: file in wrong format

Perhaps CMAKE_FIND_ROOT_PATH_MODE_PROGRAM, CMAKE_FIND_ROOT_PATH_MODE_LIBRARY, CMAKE_FIND_ROOT_PATH_MODE_INCLUDE, CMAKE_FIND_ROOT_PATH_MODE_PACKAGE should be set correctly.