Downward inference issue on negation expression with non-nullable enabled

[vsmenon]

Similar to #40022, but started seeing this on the ReleaseX64NNBD build at head this morning.

Given, I expect T in main to be inferred as bool:

T JS<T extends Object>(x) => x as T;

main() {
  if (!JS(42)) print('hi');
}

I get:

> PATH=~/dart/sdk/xcodebuild/ReleaseX64NNBD/dart-sdk/bin:$PATH dartanalyzer --enable-experiment=non-nullable cast.dart 
Analyzing cast.dart...
  error • A negation operand must have a static type of 'bool'. • cast.dart:4:8 • non_bool_negation_expression
1 error found.

I get the error above if I use ReleaseX64 as well and the experiment on.

With the experiment off and ReleaseX64, I get:

> PATH=~/dart/sdk/xcodebuild/ReleaseX64/dart-sdk/bin:$PATH dartanalyzer  cast.dart 
Analyzing cast.dart...
No issues found!

FYI - @scheglov

[scheglov]

I can reproduce it, looking quickly into the code it seems that we don't set the context type before resolving the operand.

[scheglov]

https://dart-review.googlesource.com/c/sdk/+/130921