make tests that use utf-16 not inherit the encoding for testharness.js et. al.
make tests that use utf-16 not inherit the encoding for testharness.js et. al.

RatneshThakur/testharness.js,bboyle/testharness.js,ayg/testharness.js,hallvors/testharness.js,jyasskin/testharness.js,hallvors/testharness.js,zqzhang/testharness.js,jyasskin/testharness.js