* gimple-ssa-store-merging.c: Include gimple-fold.h.
	(struct store_immediate_info): Document BIT_INSERT_EXPR stores.
	(struct merged_store_group): Add bit_insertion field.
	(dump_char_array): Use standard hexadecimal format.
	(merged_store_group::merged_store_group): Set bit_insertion to false.
	(merged_store_group::apply_stores): Use optimal buffer size.  Deal
	with BIT_INSERT_EXPR stores.  Move up code updating the mask and
	also print the mask in the dump file.
	(pass_store_merging::gate): Minor tweak.
	(imm_store_chain_info::coalesce_immediate): Fix wrong association
	of stores with groups in dump.  Allow coalescing of BIT_INSERT_EXPR
	stores with INTEGER_CST stores.
	(count_multiple_uses) <BIT_INSERT_EXPR>: New case.
	(imm_store_chain_info::output_merged_store): Add try_bitpos variable
	and use it throughout.  Generate bit insertion sequences if need be.
	(pass_store_merging::process_store): Remove redundant condition.
	Record stores from a SSA name to a bit-field with BIT_INSERT_EXPR.

From-SVN: r261089