[X86][BMI2] Test i32 intrinsics on 32/64 bits + branch off i64 tests

I had to tweak the i32 tests so we check both reg-reg and reg-mem cases.

I also added i64 load tests.

Part of ongoing work to ensure we test all intrinsic style tests on 32 and 64 bit targets where possible.

llvm-svn: 333827