Previously, YJIT assumed that basic blocks never consume more than 1 KiB of memory. This assumption does not hold for long Ruby methods such as the one in the following: ```ruby eval(<<RUBY) def set_local_a_lot #{'_=0;'*0x40000} end RUBY set_local_a_lot ``` For low `--yjit-exec-mem-size` values, one basic block could exhaust the entire buffer. Introduce a new field `codeblock_t::dropped_bytes` that the assembler sets whenever it runs out of space. Check this field in gen_single_block() to respond to out of memory situations and other error conditions. This design avoids making the control flow graph of existing code generation functions more complex. Use POSIX shell in misc/test_yjit_asm.sh since bash is expanding `0%/*/*` differently. Co-authored-by: Aaron Patterson <[email protected]>