toolchain: gcc: Add __no_instrumentation__ definition

Adds a new '__no_instrumentation__' preprocessor definition for GCC,
mapping it to '__attribute__((__no_instrument_function__))'.

This new macro is used to disable code instrumentation (enabled when
'-finstrument-functions' flag is passed to the compiler) for specific
functions when placed before a function definition.

Signed-off-by: Kevin Townsend <[email protected]>
Signed-off-by: Gustavo Romero <[email protected]>

Author: microbuilder

include/zephyr/toolchain/gcc.h

@@ -667,6 +667,12 @@ do {                                                                    \
 #define FUNC_NO_STACK_PROTECTOR
 #endif
 
+#if defined(CONFIG_INSTRUMENTATION)
+#define __no_instrumentation__ __attribute__((__no_instrument_function__))
+#else
+#define __no_instrumentation__ /**/
+#endif
+
 #endif /* !_LINKER */
 
 #define TOOLCHAIN_WARNING_ADDRESS_OF_PACKED_MEMBER "-Waddress-of-packed-member"