BranchIf and helpers were introduced when exporting the schedule from the RawMachineAssembler was not ensuring that the CFG was well-form. These methods, that were used to introduce blocks to ensure edge-split form, are now unnecessary.

BUG=

Review-Url: https://codereview.chromium.org/2426923002
Cr-Commit-Position: refs/heads/master@{#40402}