Label espressif, gnuarmemd and xtools toolchains with newlib support using
the Kconfig variable rather than relying on the TOOLCHAIN_HAS_NEWLIB
value.
Signed-off-by: Keith Packard <keithp@keithp.com>
The Zephyr cross tools configuration which the 'xtools' variant supports
enables TLS, so set TOOLCHAIN_SUPPORTS_THREAD_LOCAL_STORAGE when using it.
Signed-off-by: Keith Packard <keithp@keithp.com>