cmake: libc: minimal: Avoid linking against other libc implementations

The minimal libc is currently built as a zephyr_library and will be
included in the final link line as such. However, the c_library property
will still be set as "-lc" (for most linkers) and will be added to the
link line. This effectively requires that a separate libc implementation
be available in the toolchain and makes it possible to accidentally pull
from the non-minimal libc.

This doesn't seem desirable, so try to prevent this by clearing the
c_library property if we are using the minimal libc.

Signed-off-by: Jonathon Penix <[email protected]>

Author: jonathonpenix

lib/libc/minimal/CMakeLists.txt

@@ -1,5 +1,9 @@
 # SPDX-License-Identifier: Apache-2.0
 
+# As minimal libc will be built as a zephyr_library, clear c_library to
+# prevent accidentally requiring or linking against another libc implementation.
+set_property(TARGET linker PROPERTY c_library "")
+
 zephyr_system_include_directories(include)
 
 zephyr_library()