When patching JITed code after become of a class, the class index can look like a negative number

[tesonep]

The classIndex that we read from the JITed code might be sign extended when encoding, so we need to guarantee that we bit mask it before using it and the correct types of the variables

[guillep]

To me it looks strange. isValidClassTag: is written to assume that a correct 22bit index is passed as argument. So it's the caller's fault then:

(objectMemory isValidClassTag: (backEnd inlineCacheTagAt: mcpc asInteger))

We should make sure that inlineCacheTagAt: always returns a valid index.

[tesonep]

It is true, I will change it, also I am writting a test