fix: Incorrect lazy initialization of memory data structure

[zlangley]

No description provided.

[zlangley]

This was the main bug. If size is large (e.g., 32), then there might not be a block at address, but it's wrong to overwrite blocks at, say, address + 24. Changing this to self.initial_block_size still does not seem correct. It's obviously correct to just write blocks as needed, rather than trying to be smart about it, which is what this PR aims to do.

[github-actions]

Benchmarks

group	app_log_blowup	app_total_cells_used	app_total_cycles	app_total_proof_time_ms	leaf_log_blowup	leaf_total_cells_used	leaf_total_cycles	leaf_total_proof_time_ms	max_segment_length	instance	alloc
ecrecover_program	2	10,251,804	195,066	(+104.0 [+5.4%]) 2,037.0	-	-	-	-	1048476	64cpu-linux-arm64	mimalloc
fibonacci_program	2	51,615,800	3,000,274	(-7.0 [-0.1%]) 5,552.0	-	-	-	-	1048476	64cpu-linux-arm64	mimalloc
regex_program	2	238,890,449	8,381,808	(+64.0 [+0.4%]) 17,419.0	-	-	-	-	1048476	64cpu-linux-arm64	mimalloc
verify_fibair	2	(-1,140 [-0.0%]) 48,127,147	(-130 [-0.0%]) 397,164	(+26.0 [+0.8%]) 3,174.0	-	-	-	-	1048476	64cpu-linux-arm64	mimalloc

Commit: fcb151b

Benchmark Workflow