Avoid repeated downloads for assets during test

[jserv]

After the successful integration of #474, our GitHub CI/CD pipeline now automatically publishes a tarball of the latest RISC-V executables, keeping the rv32emu source tree clean. However, we have noticed that the tarball is being downloaded multiple times during tests, leading to unnecessary delays. To improve this, we can cache the downloaded files beforehand and simply verify the extracted RISC-V executables during the testing phase.

[vacantron]

@ChinYikMing, can you remove this line as the object file dependencies which added in #487? This will always trigger rebuilding src/* via executing make all at

rv32emu/Makefile

Line 222 in 563af8b

$(OUT)/%.o: src/%.c $(deps_emcc)

[ChinYikMing]

@ChinYikMing, can you remove this line as the object file dependencies which added in #487? This will always trigger rebuilding src/* via executing make all at

rv32emu/Makefile

Line 222 in 563af8b

$(OUT)/%.o: src/%.c $(deps_emcc)

I would prefer to keep it and only add the artifact target to deps_emcc if CC=emcc, but not the way it's currently written.

rv32emu/mk/wasm.mk

Line 2 in 563af8b

deps_emcc := artifact