[AMDGPU][GlobalISel] Update legalizer for G_ABS, G_SMIN, G_SMAX, G_UMIN, G_UMAX

There is no need to increase the size of odd sized vectors if they are
going to be scalarized by a different rule.

Patch by: Acim Maravic

Differential Revision: https://reviews.llvm.org/D155865

Author: mbrkusanin

llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp

@@ -1220,7 +1220,6 @@ AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST_,
     if (ST.hasVOP3PInsts()) {
       getActionDefinitionsBuilder({G_SMIN, G_SMAX, G_UMIN, G_UMAX, G_ABS})
         .legalFor({S32, S16, V2S16})
-        .moreElementsIf(isSmallOddVector(0), oneMoreElement(0))
         .clampMaxNumElements(0, S16, 2)
         .minScalar(0, S16)
         .widenScalarToNextPow2(0)