[flang]enable llvm-readelf and llvm-objdump (#159607)

#158125 resulted in CI failure
as `llvm-readelf` and `llvm-objcopy` were not listed in flang test deps.
This PR fixes it.

Author: anchuraj

flang/test/CMakeLists.txt

@@ -73,8 +73,10 @@ if (NOT FLANG_STANDALONE_BUILD)
     count
     not
     llvm-dis
+    llvm-objcopy
     llvm-objdump
     llvm-profdata
+    llvm-readelf
     llvm-readobj
     split-file
   )