Test compiler/c2/irTests/TestIfMinMax.java fails on RISC-V

JDK-8324655 tries to identify min/max patterns in CMoves and transform them into Min and Max nodes.
But architectures like RISC-V doesn't have support of conditional moves at the ISA level for now.
So we set ConditionalMoveLimit parameter to 0 for this platform and conditionals moves are emulated
with normal compare and branch instructions instead [1]. This is why the IR matching test added by
JDK-8324655 fails on this platform. A simple way to fix this would be skip this test for this case.

[1] https://github.com/openjdk/jdk/blob/master/src/hotspot/cpu/riscv/riscv.ad#L9775