[flang] Fix build with -DBUILD_SHARED_LIBS=ON. (llvm#3938)

The 610ded4 added more code to flang/lib/Utils/OpenMP.cpp which is not present upstream. This code have increased its dependencies which caused build to fail with -DBUILD_SHARED_LIBS=ON. This PR adds the missing dependencies.

Author: abidh

flang/lib/Utils/CMakeLists.txt

@@ -14,7 +14,12 @@ add_flang_library(FortranUtils
 
   LINK_LIBS
   FIRDialect
+  FIRBuilder
+  HLFIRDialect
 
   MLIR_LIBS
+  MLIRSupport
   MLIROpenMPDialect
+  MLIRTransformUtils
+  MLIRArithDialect
 )