[RISCV] Cleanup some V intrinsic names used in tests to match the type overloads...

[RISCV] Cleanup some V intrinsic names used in tests to match the type overloads used. Add some missing double tests on rv32. NFC

The matching for intrinsic names is forgiving about types in the
name being absent or wrong. Once the intrinsic is parsed its
name will remangled to include the real types.

This commit fixes the names to have at least enough correct types
so that the name used in the test is a prefix of the canonical name.
The big missing part is the type for the VL parameter which changes
size between rv32 and rv64.

While I was in here I noticed that we were missing some tests for
double on rv32 so I fixed that by copying from rv64 and fixing up
the VL argument type.