fcvt.s.d instruction not working with SSR

[gioelegott]

Conversion from double to single precision (fcvt.s.d) isn't working when used in combination with ssr. It hangs indefinitely on verilator but works on banshee.
This small test demonstrates the issue.
test_fcvt.zip

[and-ivanov]

This seems to be more difficult to reproduce in the latest version (11d0534). Simulation is hanging only sometimes (may require multiple reruns) when built with multithreaded support

VLT_FLAGS='--threads 16' VLT_COBJ=work-vlt/vlt/verilated_threads.o VLT_CFLAGS=-DVL_THREADED \
    make -C target/snitch_cluster bin/snitch_cluster.vlt

[colluca]

This seems to be solved by #158.