Auto merge of #117783 - tmiasko:inline-ret, r=cjgillot

 Fix insertion of statements to be executed along return edge in inlining

Inlining creates additional statements to be executed along the return
edge: an assignment to the destination, storage end for temporaries.

Previously those statements where inserted directly into a call target,
but this is incorrect when the target has other predecessors.

Avoid the issue by creating a new dedicated block for those statements.
When the block happens to be redundant it will be removed by CFG
simplification that follows inlining.

Fixes #117355

Author: bors