Backfills the standard MIT X11 header on hand-written files that never
got one, attributing each to its first-commit author and year from git
history. Code vendored from dotnet/runtime and Humanizr/Humanizer gets
its origin's license lines and a provenance note instead. Generated
files (Resources.Designer.cs, the version-info template), tool-managed
suppression files, and BAML test-case fixtures intentionally stay
header-less.
Assisted-by: Claude:claude-fable-5:Claude Code
Unreachable code is not part of the dominator tree, which most of our transforms are based on.
In particular, dominance-based loop detection runs into the problem where unreachable code might have jumps into two independent loops. In that case, it's impossible to place the unreachable code in a way that avoids assertions / generating invalid C#.
We establish the invariant that all blocks in a BlockContainer must be statically reachable from the entry point (-> every block is part of the dominator tree). This means transforms no longer have to deal with special cases for unreachable code.
The "Remove dead and side effect free code" option still has an effect on dead stores, but unreachable code is now always removed (previously this also was dependent on this option).