Fix concurrent sweeping in predictable mode and bring --concurrent-sweeping flag back.

BUG=
R=jochen@chromium.org

Review URL: https://codereview.chromium.org/726363002

Cr-Commit-Position: refs/heads/master@{#25370}
Fix one more missing c0_ < 0 check in scanner

BUG=chromium:433766
LOG=n
R=jarin@chromium.org

Review URL: https://codereview.chromium.org/731953003

Cr-Commit-Position: refs/heads/master@{#25371}
Remove left-over generated runtime test from mjsunit.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/734633002

Cr-Commit-Position: refs/heads/master@{#25372}
Generalize ScaledWithOffsetMatcher to support 64 bits

Preparation for supporting more addressing modes in instruction selection.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/729853005

Cr-Commit-Position: refs/heads/master@{#25373}
Fix Windows build after 25373

R=bmeurer@chromium.org
TBR=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/733783003

Cr-Commit-Position: refs/heads/master@{#25374}