Handling the case when runtime.Caller(2) returns ok as false in assert.go

[lazysegtree]

Since the skip value is always 2, and its probably guaranteed that runtime.Caller() will not fail due to skip being greater than number of stack frames. But I think could fail due to some unexpected issues - something specific to user system, or some memory corruption.

I think, it shouldn't hurt to add a check for the ok value, in case it is false, for a more complete error handling.

func Caller(skip int) (pc uintptr, file string, line int, ok bool)

The boolean ok is false if it was not possible to recover the information.

Reference :

• https://pkg.go.dev/runtime#Caller
• https://go.dev/src/runtime/symtab_test.go

[lazysegtree]

Please tell me what do you think about this @nikoksr .
If you are okay with this I can raise a PR for this.