psym_lbrace_block
ps.lbrace_kind = psym_lbrace_block;
ps.lbrace_kind = psym_lbrace_block;
if (lsym == lsym_lbrace && ps.lbrace_kind == psym_lbrace_block
return psym == psym_lbrace_block
case psym_lbrace_block: