Should Be Able to Attach to 64bit Regardless of Btiness

[MrayerMSFT]

Since we no longer examine modules, we can safely attach to any process as long as they are verified as a PowerShell host. This task simply requires removing the following from AttachToProcess:

IsWow64Process(process.Handle, out is64Bit);
if (!Environment.Is64BitProcess && is64Bit)
{
    // cannot examine a 64 bit process' modules from a 32 bit process
    return false;
}

(remove definition of IsWow64Process as well)