ART: Fixes for constructor parameter annotations

Synthesize empty parameter annotations for implicit parameters on
constructors. Reflective methods for recovering parameter annotations
expect them to be present though they may not be present in the DEX file.

(cherry-picked from commit 58143d2c)

Bug: b/68033708
Test: art/test/run-test --host 715
Change-Id: I0827c7e71ff7c7e044fc9dd6c5aac639a0e1a4c6