[OpenMP] Update the bitcode library install and search path

Summary:
This was accidentally kept in the old location when we moved to the
new `lib/<triple>/` location for the DeviceRTL. Move this to reduce the
delta with #136729.

Author: jhuber6

clang/lib/Driver/ToolChains/CommonArgs.cpp

@@ -2794,6 +2794,11 @@ void tools::addOpenMPDeviceRTL(const Driver &D,
   for (const auto &LibPath : HostTC.getFilePaths())
     LibraryPaths.emplace_back(LibPath);
 
+  // Check the target specific library path for the triple as well.
+  SmallString<128> P(D.Dir);
+  llvm::sys::path::append(P, "..", "lib", Triple.getTriple());
+  LibraryPaths.emplace_back(P);
+
   OptSpecifier LibomptargetBCPathOpt =
       Triple.isAMDGCN()  ? options::OPT_libomptarget_amdgpu_bc_path_EQ
       : Triple.isNVPTX() ? options::OPT_libomptarget_nvptx_bc_path_EQ

offload/DeviceRTL/CMakeLists.txt

@@ -137,7 +137,7 @@ function(compileDeviceRTLLibrary target_name target_triple)
                       "-r" "-nostdlib" "-flto" "-Wl,--lto-emit-llvm" "-march=")
   install(TARGETS libomptarget-${target_name}
           PERMISSIONS OWNER_WRITE OWNER_READ GROUP_READ WORLD_READ
-          DESTINATION ${OFFLOAD_INSTALL_LIBDIR})
+          DESTINATION "lib${LLVM_LIBDIR_SUFFIX}/${target_triple}")
 
   add_library(omptarget.${target_name}.all_objs OBJECT IMPORTED)
   set_property(TARGET omptarget.${target_name}.all_objs APPEND PROPERTY IMPORTED_OBJECTS