[LV] Improve AnyOf reduction codegen. (#78304)

Update AnyOf reduction code generation to only keep track of the AnyOf
property in a boolean vector in the loop, only selecting either the new
or start value in the middle block.

The patch incorporates feedback from https://reviews.llvm.org/D153697.

This fixes the #62565, as now there aren't multiple uses of the
start/new values.

Fixes https://github.com/llvm/llvm-project/issues/62565

PR: https://github.com/llvm/llvm-project/pull/78304