c: Check for modifiable static compound literals in inline definitions

c: Check for modifiable static compound literals in inline definitions

The C rule against modifiable objects with static storage duration in
inline definitions should apply to compound literals (using the C2x
feature of storage-class specifiers for compound literals) just as to
variables.  Add a call to record_inline_static for compound literals
to make sure this case is detected.

Bootstrapped with no regressions for x86_64-pc-linux-gnu.

gcc/c/
	* c-decl.cc (build_compound_literal): Call record_inline_static.

gcc/testsuite/
	* gcc.dg/c2x-complit-8.c: New test.