strings: HasSuffix doesn't work correctly for multibyte runes in go 1.26 [1.26 backport]

[gopherbot]

@seankhliao requested issue #77613 to be considered for backport to the next 1.26 minor release.

@gopherbot please open a backport issue for go 1.26

[gopherbot]

Change https://go.dev/cl/745840 mentions this issue: cmd/compile: avoid folding 64-bit integers into 32-bit constants

[gopherbot]

Closed by merging CL 745840 (commit 4659d63) to release-branch.go1.26.