Revert "std.math.modf: disable vector test on LoongArch with LSX"

This reverts commit 35d2b1e99a2bf57f76d3317061a1b74d145f3c59.

The bug was fixed in LLVM 22.
35b5a4f5f8Alex Rønne Petersen committed on 2/19/2026, 6:14:07 PMparent3eb3a8b
1 file changedLine totals unavailable