expand: Fix up ICE on VCE from _Complex types to _BitInt [PR117458]

expand: Fix up ICE on VCE from _Complex types to _BitInt [PR117458]

extract_bit_field can't handle extraction of non-mode precision
from complex mode operands which don't live in memory, e.g. gen_lowpart
crashes on those.
The following patch in that case defers the extract_bit_field call
until op0 is forced into memory.

2024-11-19  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/117458
	* expr.cc (expand_expr_real_1) <case VIEW_CONVERT_EXPR>: Don't
	call extract_bit_field if op0 has complex mode and isn't a MEM,
	instead first force op0 into memory and then call extract_bit_field.

	* gcc.dg/bitint-116.c: New test.