For now, we didn't set the default operation action for SIGN_EXTEND_INREG for vector type, which is 0 by default, that is legal. However, most target didn't have native instructions to support this opcode. It should be set as expand by default, as what we did for ANY_EXTEND_VECTOR_INREG.
This become critical as some target(i.e. Mips) didn't set it as expand for vector type, which will have problems as they didn't have the native instruction for it.
This patch will set the default operation action for SIGN_EXTEND_INREG for vector type as expand. And grep all the targets that specify its match pattern for vector type and make it legal.