+/* Parse one block of code (a statement or brace-delimited stanza).
+ This is used by the IF, DO, FOR, OBJECTLOOP, SWITCH, and WHILE
+ statements.
+ (Note that this is *not* called by the top-level parse_routine()
+ handler.)
+ The break_label and continue_label arguments are the labels in
+ the calling block to jump to on "break" or "continue". -1 means
+ we can't "break"/"continue" here (because we're not in a loop/switch).
+ If switch_rule is true, we're in a switch block; case labels are
+ accepted.
+*/