[libomptarget][amdcgn] Add build dependency for llvm-link and opt

D107156 and D107320 are not sufficient when OpenMP is built as llvm runtime
(LLVM_ENABLE_RUNTIMES=openmp) because dependencies only work within the same
cmake instance.

We could limit the dependency to cases where libomptarget/plugins are really
built. But compared to the whole llvm project, building openmp runtime is
negligible and postponing the build of OpenMP runtime after the dependencies
are ready seems reasonable.

The direct dependency introduced in D107156 and D107320 is necessary for the
case where OpenMP is built as llvm project (LLVM_ENABLE_PROJECTS=openmp).

Differential Revision: https://reviews.llvm.org/D108404

llvm/runtimes/CMakeLists.txt

@@ -350,15 +350,19 @@ if(runtimes)
   # Create a runtimes target that uses this file as its top-level CMake file.
   # The runtimes target is a configuration of all the runtime libraries
   # together in a single CMake invocaiton.
+  if("openmp" IN_LIST LLVM_ENABLE_RUNTIMES)
+    message(STATUS "Adding dependencies opt llvm-link")
+    set(extra_deps opt llvm-link)
+  endif()
   if(NOT LLVM_RUNTIME_TARGETS)
     runtime_default_target(
-      DEPENDS ${deps}
+      DEPENDS ${deps} ${extra_deps}
       PREFIXES ${prefixes})
     set(test_targets check-runtimes)
   else()
     if("default" IN_LIST LLVM_RUNTIME_TARGETS)
       runtime_default_target(
-        DEPENDS ${deps}
+        DEPENDS ${deps} ${extra_deps}
         PREFIXES ${prefixes})
       list(REMOVE_ITEM LLVM_RUNTIME_TARGETS "default")
     else()

openmp/libomptarget/DeviceRTL/CMakeLists.txt

@@ -151,6 +151,7 @@ endif()
 
 # Create target to build all Bitcode libraries.
 add_custom_target(omptarget-new-nvptx-bc)
+add_dependencies(omptarget-new-nvptx-bc opt llvm-link)
 
 # Generate a Bitcode library for all the compute capabilities the user requested
 foreach(sm ${nvptx_sm_list})
@@ -197,6 +198,7 @@ foreach(sm ${nvptx_sm_list})
 
   add_custom_target(${bclib_target_name} ALL DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${bclib_name}_opt)
   add_dependencies(omptarget-new-nvptx-bc ${bclib_target_name})
+  add_dependencies(${bclib_target_name} opt llvm-link)
 
   # Copy library to destination.
   add_custom_command(TARGET ${bclib_target_name} POST_BUILD

openmp/libomptarget/deviceRTLs/amdgcn/CMakeLists.txt

@@ -157,7 +157,7 @@ foreach(mcpu ${mcpus})
   add_custom_command(
     OUTPUT ${bc_libname}
     COMMAND ${LINK_TOOL} ${bc_files} | ${OPT_TOOL} --always-inline -o ${OUTPUTDIR}/${bc_libname}
-    DEPENDS ${bc_files} opt)
+    DEPENDS ${bc_files} llvm-link opt)
 
   add_custom_target(lib${libname}-${mcpu} ALL DEPENDS ${bc_libname})