Fix firstRange and lastRange implementation in DataProtocol

[Frizlab]

firstRange did not find needle if at last index of haystack.
lastRange was fully broken and crashed.

[Frizlab]

Hopefully I got it right this time

[varungandhi-apple]

cc @phausler: would you be the right person to review?

[spevans]

@swift-ci test

[YOCKOW]

#2499 will fix the same bug(SR-10689).
Who would decide which PR should be chosen?

EDIT: FYI
The same implementation with #2499 for SDK Overlay was already merged:

• SR-10689: Fix bugs of DataProtocol's firstRange(of:in:)/lastRange(of:in:). swift#28639
• 1cf2e3b

[millenomi]

Oh, geez, this fell through the cracks while I am Away On Adventures.

@YOCKOW is your cherry-pick on the main branch of this repository already?

[millenomi]

And if so: is @Frizlab's patch fixing a different issue than that?

[millenomi]

I'm happy to take this patch if it's needed.

[YOCKOW]

@millenomi

I believe #2499 is ready to be merged into main branch because:

• It has been open since Sep 2019.
• The last tests have passed all.
• It has no conflicts with the main branch.
• (As above,) The same implementation with it for SDK Overlay was already merged.

@Frizlab's patch (this PR) seems to be fixing the same issue.

[Frizlab]

Personally I don’t care which PR is merged as long as the issue is fixed.

[CodaFi]

@swift-ci test

[YOCKOW]

FYI: #2499 was merged into main. The issue (SR-10689) is fixed.

[Frizlab]

Closing as all tests introduced in this PR now pass with the merging of #2499.