Why not build riscv-tests for rv32ima?

Hi, I'm new to rocket chip.
I compared build.sh and build-rv32ima.sh, and I found that the build flags are not exactly the same (--enable-jtag_vpi for riscv-openocd, --disable-gdb for riscv-gnu-toolchain) and the riscv-tests is not built. Is there any specific reason for that?

I looked a bit and I found that add this line in build-rv32ima.sh seems to build the riscv-tests in rv32 context (I haven't run a test yet so I'm not so sure):
```
build_project riscv-tests --prefix=$RISCV/riscv32-unknown-elf --with-xlen=32
```

Compare build.sh with build-rv32ima.sh, focusing on the riscv-openocd, riscv-gnu-toolchain, and riscv-tests build steps. Run build-rv32ima.sh with the proposed riscv-tests command and verify whether the rv32 tests build successfully; document the reason for any differing flags and the expected completed build behavior.

Written by the indexing model from the issue text.