Fix Idx1 of BranchStatement so that it points to the character after the label if Label exists, or the one after Token if Label does not exist.
Fix Idx1 of LabelledStatement so that it points to the character after the statement.
Fix Idx1 of ReturnStatement so that it points to the character after the argument if Argument exists, or the one after return keyword if Argument does not exist.
Set Idx0 of SwitchStatement and fix Idx1 of SwitchStatement so that it points to the character after the right brace.
Fix Idx0 of ThrowStatement to point to the start of throw keyword and fix Idx1 of ThrowStatement so that it points to the next character after Argument.
Fix Idx1 of TryStatement to point to the character after Finally if Finally exists, or after Catch if Finally does not exist.
Set Idx0 of WithStatement which was not previously set.
Set WhileStatement.While so that Idx0 points to the right place.
Set Idx0 of DoWhileStatement and fix Idx1 to point to the next character after the right parenthesis.