RFR: 8263769: simplify PhaseMacroExpand::extract_call_projections()

[Xin Liu]

PhaseMacroExpand::extract_call_projections(macro.cpp) is almost identical to 
CallNode::extract_projections(callnode.cpp). The implementation can be replaced
by CallNode::extract_projections.

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Commit messages:
 - 8263769: simplify PhaseMacroExpand::extract_call_projections()

Changes: https://git.openjdk.java.net/jdk/pull/3105/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3105&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8263769
  Stats: 53 lines in 1 file changed: 0 ins; 39 del; 14 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3105.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3105/head:pull/3105

PR: https://git.openjdk.java.net/jdk/pull/3105