* dotnet/master: (918 commits)
  Pure null test on unconstrained type (dotnet#41384)
  Fix file headers, bootsrap build issues.
  Make `elementLocations` accept an array of nullable locations in the public api.
  Learn from non-null tests on as operator (dotnet#41419)
  Use Microsoft.NET.Sdk.WindowsDesktop for XAML projects (dotnet#40234)
  Address feedback.
  Introduce `GetRequiredBinder`.
  Add missing `NotNullWhen` annotations.
  Annotate more of the binder
  Add version of zlib library to deterministic build inputs (dotnet#41385)
  [master] Update dependencies from dotnet/arcade (dotnet#41354)
  Simplify
  Simplify
  Do not simplify interpolation expressions on implicit receivers.
  Fix local function crash + add tests
  Substituted symbol equality (dotnet#41123)
  Fix test failures
  Rename from IncludeNonNullableReferenceTypeModifier to IncludeNotNullableReferenceTypeModifier (dotnet#41332)
  Set TEMP environment variable to $TempDir on CI machines (dotnet#41361)
  Document placeholders
  ...