v0.84.0

Likely to cause new Flow errors:

• Earlier, type constraints between any and other types would be dropped. Instead, they are now
  propagated. In some cases, this unblocks further constraint solving and helps find more errors.
• When a variable is equality-checked with a literal, the variable's type is refined. Earlier, if
  the variable's type was incompatible with the literal's type, it would silently be refined to
  empty, whereas now this is an error.

New Features:

• Added support for wildcard (_) type arguments to function / constructor calls. This is
  especially useful when some type arguments are sufficient to pin down the type of the result; the
  others can simply be _.

Notable bug fixes:

• Fixed a case that would crash get-def and find-refs
• Fixed a bug with unreachability analysis for ternary expressions
• Fixed a bug with refinements merging at the end of switch statements

Misc:

• Fixed various AST printing / layout bugs
• Made various improvements to the AST differ
• Refactored parts of get-def and find-refs to reuse code
• Made progress on abstracting locations in the core type inference engine
• Made progress on module signature verification and generation
• Merged PRs that improve type declarations: e.g., getBoundingClient returns a DOMRect instead of a ClientRect.

Parser:

• Support for ... to indicate inexactness in object types