PR c/42439
	* c-decl.c (check_bitfield_type_and_width): Only pedwarn if
	pedantic for bit-field width not an integer constant expression
	but folding to one.

testsuite:
	* gcc.dg/bitfld-19.c, gcc.dg/bitfld-20.c, gcc.dg/bitfld-21.c: New
	tests.

From-SVN: r155526