temporarily test if we can at least build offload without openmp

Author: ZuseZ4

src/bootstrap/src/core/build_steps/llvm.rs

@@ -460,7 +460,7 @@ impl Step for Llvm {
             enabled_llvm_runtimes.push("offload");
             //FIXME(ZuseZ4): LLVM intends to drop the offload dependency on openmp.
             //Remove this line once they achieved it.
-            enabled_llvm_runtimes.push("openmp");
+            //enabled_llvm_runtimes.push("openmp");
             //enabled_llvm_runtimes.push("compiler-rt");
 
             //  -DRUNTIMES_CMAKE_ARGS="-DLIBOMPTARGET_PLUGINS_TO_BUILD=amdgpu;nvptx;