Refactor builder intrinsic tests.

Move tests for building HIR for intrinsics in instruction
builder to a single test. Remove duplicate rotate tests.

Enable these tests on the RI (some were disabled in the
known failures, some by using src-art, some were enabled).

Drop the unnecessary `--experimental method-handles`-passing
build script that used to be in 709-checker-varhandles.

Test: testrunner.py --host --optimizing --jvm
      (Ignore pre-existing --jvm failures.)
Change-Id: Iee799c5f5daa6b1ba711e834fb93156c5e5e8fa8
31 files changed