Change the name of LLVM libc package to be easier to identify (#393)

Now `ATfE-*-Linux-x86_64.tar.xz` matches both packages, making one
`ATfE_llvmlibc-*-Linux-x86_64.tar.xz` will make it distinct and easier
to handle in scripts.

Author: voltur01

arm-software/embedded/CMakeLists.txt

@@ -504,7 +504,7 @@ else()
     if(LLVM_TOOLCHAIN_C_LIBRARY STREQUAL "picolibc")
         set(PACKAGE_FILE_NAME ${PACKAGE_NAME}-${PACKAGE_VERSION}-${CPACK_SYSTEM_NAME})
     else()
-        set(PACKAGE_FILE_NAME ${PACKAGE_NAME}-${PACKAGE_VERSION}-${LLVM_TOOLCHAIN_C_LIBRARY}-${CPACK_SYSTEM_NAME})
+        set(PACKAGE_FILE_NAME ${PACKAGE_NAME}_${LLVM_TOOLCHAIN_C_LIBRARY}-${PACKAGE_VERSION}-${CPACK_SYSTEM_NAME})
     endif()
 endif()
 set(CPACK_PACKAGE_FILE_NAME ${PACKAGE_FILE_NAME})