[tree-ssa] Improve removal of statements when removing blocks

[Jason Merrill]

On Wed, 16 Jul 2003 19:11:55 -0600, law@redhat.com wrote:

> Unfortunately, the code which linearizes a COND_EXPR which is always
> true requires an ELSE clause which is empty -- a COMPOUND_EXPR with
> both operands being empty statements does not qualify as empty, nor does
> a chain of COMPOUND_EXPRs where all the leafs are empty statements.

This is why we should be checking TREE_SIDE_EFFECTS rather than
IS_EMPTY_STMT in most cases.

Jason