Build system does not propagate 64-bit caps to cheri-cap-lib

[Jerryxia32]

Build with RV32IMUxCHERI bluesim fails.

After some debugging I found the cheri-cap-libs/CHERICC_Fat.bsv does not pick up anything from Flute upper level about the fact that it is compiling 64-bit caps, and fails with:

compiling ../../src_Core/ISA/ISA_Decls.bsv
Error: "../../src_Core/ISA/ISA_Decls_CHERI.bsvi", line 113, column 38: (T0020)
  Type error at:
    new_csr

  Expected type:
    Bit#(64)

  Inferred type:
    ISA_Decls::WordXL

make: *** [../../builds/Resources/Include_bluesim.mk:18: compile] Error 1
make: Leaving directory '/root/Flute/builds/RV32IMUxCHERI_Flute_bluesim'

Manually forcing things in CHERICC_Fat.bsv to be 64-bit caps works.