Wrong type inference on array when setting values on it

[VincentLanglet]

Bug report

Code snippet that reproduces the problem

(https://phpstan.org/r/183caf26-e741-46be-b8ab-b93af9f082aa)

Expected output

No error, the array should be considered as array{foo?: int, bar?: int}

Did PHPStan help you today? Did it make you happy in any way?

Sure

[VincentLanglet]

Similar issue https://phpstan.org/r/74a8382c-f6bf-4fca-a378-100ca2568cae

The array is inferred as array{bar: int<min, -1>, foo: int<1, max>}
but foo and bar can never be set in the same time.

Same issue with if/else: https://phpstan.org/r/4941e906-0ee4-462c-9aa7-93c98a9772d7

I can also try to fix it, if you have an idea where I should look @ondrejmirtes

[phpstan-bot]

@VincentLanglet After the latest commit in 1.6.x, PHPStan now reports different result with your code snippet:

@@ @@
-20: Offset 'foo' on array{bar: int<min, 0>, foo: int<1, max>} in isset() always exists and is not nullable.
+No errors

[phpstan-bot]

@VincentLanglet After the latest commit in 1.6.x, PHPStan now reports different result with your code snippet:

@@ @@
-21: Offset 'foo' on array{bar: int<min, -1>, foo: int<1, max>} in isset() always exists and is not nullable.
+No errors