Load prototype from map in PropertyHandlerCompiler::CheckPrototypes.

BUG=v8:3629
LOG=N
TBR=verwaest@chromium.org

Review URL: https://codereview.chromium.org/753223002

Cr-Commit-Position: refs/heads/master@{#25490}
[turbofan] Fix matching of the lea instruction.

Resets the scaled exponent to 0 when the scaling match fails.

BUG=

Review URL: https://codereview.chromium.org/756643002

Cr-Commit-Position: refs/heads/master@{#25491}