* Fix expando handling in getTypeReferenceType
getExpandoSymbol looks for the initialiser of a symbol when it is an
expando value (IIFEs, function exprs, class exprs and empty object
literals) and returns the symbol.
Previously, however, it returned the symbol of the initialiser without
merging with the declaration symbol itself. This missed, in particular,
the prototype assignment in the following pattern:
```js
var x = function x() {
this.y = 1
}
x.prototype = {
z() { }
}
/** @type {x} */
var xx;
xx.z // missed!
```
getJSDocValueReference had weird try-again code that relied on calling
getTypeOfSymbol, which *does* correctly merge the symbols. This PR
re-removes that code and instead makes getExpandoSymbol call
mergeJSSymbols itself.
* Remove extra newline
* Restore delayed merge check to getTypeFromJSDocValueReference
This is needed when a function merges with a prototype assignment. The
resulting *merged* symbol is a constructor function marked with
SymbolFlags.Class. However, the merge doesn't happen until
getTypeOfFuncClassEnumModule is called, which, in the
getTypeReferenceType code path, doesn't happen until
getTypeFromJSDocValueReference. That means the check for
SymbolFlags.Class is missed.
Previously, getTypeFromJSDocValueReference had a weird check
`symbol !== getTypeOfSymbol(symbol).symbol`, which, if true, ran
getTypeReferenceType again on `getTypeOfSymbol(symbol).symbol`. For
JS "aliases", this had the effect of dereferencing the alias, and for
function-prototype merges, this had the effect of ... just trying again
after the merge had happened.
This is a confusing way to run things. getTypeReferenceType should
instead detect a function-prototype merge, cause it to happen, and
*then* run the rest of its code instead of relying on try-again logic at
the very end. However, for the RC, I want to fix this code by restoring
the old check, with an additional check to make sure that #33106 doesn't
break again:
```ts
const valueType = getTypeOfSymbol(symbol)
symbol !== valueType.symbol && getMergedSymbol(symbol) === valueType.symbol
```
I'll work on the real fix afterwards and put it into 3.8.
* Add bug number
