Sema: fix merging stores instructions from a comptime struct value with `-fstrip`
The first instruction in the block was never checked resulting in `struct_is_comptime` being incorrectly cleared if there are no instructions before the first field of the comptime struct.
Fixes #17119
b0dba46800cfillion committed on 12/28/2023, 12:44:26 PM· committed by Veikka Tuominenparentff17b11