[ARM] Select VMAXNM and VMINNM regardless of operand order

[ARM] Select VMAXNM and VMINNM regardless of operand order

Currently, the ARM backend will select the VMAXNM and VMINNM for these C
expressions:
  (a < b) ? a : b
  (a > b) ? a : b
but not these expressions:
  (a > b) ? b : a
  (a < b) ? b : a

This patch allows all of these expressions to be matched.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220671 91177308-0d34-0410-b5e6-96231b3b80d8