adjust docs to latest offload usage

src/offload/usage.md

@@ -89,38 +89,21 @@ Now we generate the device (GPU) code, passing the manifest:
 ```
 RUSTFLAGS="-Ctarget-cpu=gfx90a --emit=llvm-bc,llvm-ir -Zoffload=Device=/absolute/path/to/offload.manifest -Csave-temps -Zunstable-options" cargo +offload build -Zunstable-options -r -v --target amdgcn-amd-amdhsa -Zbuild-std=core
 ```
-You might afterwards need to copy your target/release/deps/<lib_name>.bc to lib.bc for now, before the next step.
 
-Now we generate the host (CPU) code.
+Next we generate the host (CPU) code.
 ```
-RUSTFLAGS="--emit=llvm-bc,llvm-ir -Csave-temps -Zoffload=Host=/p/lustre1/drehwald1/prog/offload/r/target/amdgcn-amd-amdhsa/release/deps/device.bin -Zunstable-options" cargo +offload build -r
-```
-This call also does a lot of work and generates multiple intermediate files for LLVM offload.
-While we integrated most offload steps into rustc by now, one binary invocation still remains for now:
-
-```
-"clang-linker-wrapper" "--should-extract=gfx90a" "--device-compiler=amdgcn-amd-amdhsa=-g" "--device-compiler=amdgcn-amd-amdhsa=-save-temps=cwd" "--device-linker=amdgcn-amd-amdhsa=-lompdevice" "--host-triple=x86_64-unknown-linux-gnu" "--save-temps" "--linker-path=/ABSOlUTE_PATH_TO/rust/build/x86_64-unknown-linux-gnu/lld/bin/ld.lld" "--hash-style=gnu" "--eh-frame-hdr" "-m" "elf_x86_64" "-pie" "-dynamic-linker" "/lib64/ld-linux-x86-64.so.2" "-o" "main" "/lib/../lib64/Scrt1.o" "/lib/../lib64/crti.o" "/ABSOLUTE_PATH_TO/crtbeginS.o" "-L/ABSOLUTE_PATH_TO/rust/build/x86_64-unknown-linux-gnu/llvm/bin/../lib/x86_64-unknown-linux-gnu" "-L/ABSOLUTE_PATH_TO/rust/build/x86_64-unknown-linux-gnu/llvm/lib/clang/21/lib/x86_64-unknown-linux-gnu" "-L/lib/../lib64" "-L/usr/lib64" "-L/lib" "-L/usr/lib" "target/<GPU_DIR>/release/host.o" "-lstdc++" "-lm" "-lomp" "-lomptarget" "-L/ABSOLUTE_PATH_TO/rust/build/x86_64-unknown-linux-gnu/llvm/lib" "-lgcc_s" "-lgcc" "-lpthread" "-lc" "-lgcc_s" "-lgcc" "/ABSOLUTE_PATH_TO/crtendS.o" "/lib/../lib64/crtn.o"
-```
-
-You can try to find the paths to those files on your system.
-However, I recommend to not fix the paths, but rather just re-generate them by copying a bare-mode OpenMP example and compiling it with your clang.
-By adding `-###` to your clang invocation, you can see the invidual steps.
-It will show multiple steps, just look for the clang-linker-wrapper example.
-Make sure to still include the path to the `host.o` file, and not whatever tmp file you got when compiling your c++ example with the following call.
-```
-myclang++ -fuse-ld=lld -O3 -fopenmp  -fopenmp-offload-mandatory --offload-arch=gfx90a omp_bare.cpp -o main -###
+RUSTFLAGS="--emit=llvm-bc,llvm-ir -Csave-temps -Zoffload=Host=$PWD/target/amdgcn-amd-amdhsa/release/deps/device.bin -Zunstable-options" cargo +offload build -r
 ```
 
 In the final step, you can now run your binary
 
 ```
-./main
+LD_LIBRARY_PATH=$(rustc +nightly --print sysroot)/lib  ./target/x86_64-unknown-linux-gnu/release/binary-name
 all checks passed!
 ```
 
-To receive more information about the memory transfer, you can enable info printing with
-```
-LIBOMPTARGET_INFO=-1  ./main
-```
+These three steps will soon be wrapped into a single command, once we had more time to test all steps.
+
+To receive more information about the memory transfer, you can enable info printing by adding `LIBOMPTARGET_INFO=-1` ahead of your binary call.
 
 [^list]: https://rocm.docs.amd.com/en/latest/reference/gpu-arch-specs.html or https://developer.nvidia.com/cuda/gpus. Alternatively, check `rustc --print target-cpus`.