The function inlining information is decided in advance and maintained
in the callgraph as so called inline plan.
For each inlined call, the callee's node is cloned to represent the
- new function copy produced by inlininer.
+ new function copy produced by inliner.
Each inlined call gets a unique corresponding clone node of the callee
and the data structure is updated while inlining is performed, so
the clones are eliminated and their callee edges redirected to the