This patch fixes an interesting bug in default_target_compile:  if the options set dest= prior to specifying a language, the language defaults are loaded incorrectly.  Specifically, for each board_info value, the *existence* of that value is tested for the board specified using dest=, but the actual value is
read from the information for the current target.  Since the current target is the default destination, the only reason to specify the dest= option is to override the current target, so this must be wrong and this patch fixes the bug.