Eliminate -Wno-enum-compare-switch (#106)
Eliminate -Wno-enum-compare-switch (#106)

Was required for third_party/icu under clang-6.0 but appears to be no
longer necessary after flutter/engine#4005. Originally introduced in
b9b34ded1a2e6e5ed8637fac996e0f8bd67ad417.
flutter/buildroot,flutter/buildroot,flutter/buildroot,flutter/buildroot