Investigate and Fix Failing Hermes Tests

[iamAbhi-916]

The following Hermes tests are currently failing and need investigation and resolution:

• Hermes :: BCGen/HBC/deltamode/string-functions-update.js
• Hermes :: hermes/TypedArray.js
• Hermes :: hermes/array-functions.js
• Hermes :: hermes/number-functions.js
• Hermes :: hermes/proxy.js
• Hermes :: hermes/string-functions.js

Steps to test

Build command from build.js after adding check-hermes rule in build.js 
node .ado\scripts\build.js --no-build --jstest --output-path out --platform x64 --configuration release

using cmake without build.js

command to execute within hermes-windows/build 
cmake --build . --target check-hermes --config Release release

[vmoroz]

@iamAbhi-916 , just to confirm: to run the JS tests we must build the check-hermes target, right?