ART: Clean up loop construction in gtests.

Define and use helper functions for creating loops and
linear loop variables.

Also remove a dead `HAdd` from one BCE test and change a
copy-pasted BCE test for `a[i %200]` to actually test that
case (which also reverses the expectation).

This change adds extra blocks to some tests, for example
empty loop pre-headers, additional return blocks with
`HReturnVoid` and a single-goto block to split a critical
edge (in `BubbleSortArrayBoundsElimination`). It also adds
some extra `HGoto` and `HReturnVoid` instructions and
reorders some instructions (linear loop variable
increments are added earlier).

LSE test helper function `CreateTestControlFlowGraph()`
was changed to reorder successors, effectively changing
    i = 0; do { ... } while (i++ >=128);
to
    i = 0; do { ... } while (i++ < 128);
with no impact on the tests using it.

`SuperblockClonerTest.IndividualInstrCloner` now clones one
additional `HGoto`.

Test: m test-art-host-gtest
Change-Id: Ie53b07429e62159dee7bfc719c59e06d2609a70e

0 files changed, 0 insertions, 0 deletions