File _constraints of Package ghc

<constraints>
  <hardware>
    <disk>
      <size unit="G">12</size>
    </disk> 
    <physicalmemory>
      <size unit="G">4</size>
    </physicalmemory>
  </hardware>
  <overwrite>
    <conditions>
      <arch>riscv64</arch>
    </conditions>
    <hardware>
      <physicalmemory>
	<size unit="G">20</size>
      </physicalmemory>
    </hardware>
  </overwrite>
</constraints>