[ValueTracking] Fix a bug for signed min-max clamping (#121206)

Correctly handle the case where the clamp is over the full range.
This fixes an issue introduced in #121206.

[ValueTracking] Improve KnownBits for signed min-max clamping (#120576)

A signed min-max clamp is the sequence of smin and smax intrinsics,
which constrain a signed value into the range: smin <= va

[ValueTracking] Improve KnownBits for signed min-max clamping (#120576)

A signed min-max clamp is the sequence of smin and smax intrinsics,
which constrain a signed value into the range: smin <= value <= smax.
The patch improves the calculation of KnownBits for a value subjected to
the signed clamping.

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