[Flang][CMake] Add explicit libFortranCommon dependency for f18 etc.

[ro]

Summary

When I tried Solaris builds with -DBUILD_SHARED_LIBS=ON, some commands failed
to link:

[ 94%] Linking CXX executable ../../../../bin/f18
Undefined                       first referenced
 symbol                             in file
Fortran::common::IntrinsicTypeDefaultKinds::set_sizeIntegerKind(int) CMakeFiles/f18.dir/f18.cpp.o  (symbol belongs to implicit dependency /var/llvm/local-amd64-release-shared-gcc8-make/lib/libFortranCommon.so.11git)
Fortran::common::IntrinsicTypeDefaultKinds::set_subscriptIntegerKind(int) CMakeFiles/f18.dir/f18.cpp.o  (symbol belongs to implicit dependency /var/llvm/local-amd64-release-shared-gcc8-make/lib/libFortranCommon.so.11git)
Fortran::common::EnumIndexToString[abi:cxx11](int, char const*) CMakeFiles/f18.dir/f18.cpp.o  (symbol belongs to implicit dependency /var/llvm/local-amd64-release-shared-gcc8-make/lib/libFortranCommon.so.11git)
Fortran::common::IntrinsicTypeDefaultKinds::set_defaultIntegerKind(int) CMakeFiles/f18.dir/f18.cpp.o  (symbol belongs to implicit dependency /var/llvm/local-amd64-release-shared-gcc8-make/lib/libFortranCommon.so.11git)
Fortran::common::IntrinsicTypeDefaultKinds::IntrinsicTypeDefaultKinds() CMakeFiles/f18.dir/f18.cpp.o  (symbol belongs to implicit dependency /var/llvm/local-amd64-release-shared-gcc8-make/lib/libFortranCommon.so.11git)
Fortran::common::IntrinsicTypeDefaultKinds::set_defaultRealKind(int) CMakeFiles/f18.dir/f18.cpp.o  (symbol belongs to implicit dependency /var/llvm/local-amd64-release-shared-gcc8-make/lib/libFortranCommon.so.11git)
ld: fatal: symbol referencing errors

This patch fixes this by adding explicit dependencies on libFortranCommon to the
affected commands.

Tested on amd64-pc-solaris2.11, sparcv9-sun-solaris2.11, and
x86-64-pc-linux-gnu. Ok for master?

[DavidTruby]

I think we should make the libraries have transitive dependencies so that you can choose to link only against the one that you think you're using. For example, linking against any of the other libraries should link against FortranCommon anyway I believe?
This should be doable with CMake's target properties, perhaps the add_flang_library should do this.

The change itself looks fine though, if it fixes builds for you I think you can merge it while we look at doing what I suggest above.

[DavidTruby]

@ro are you able to commit this or do you need someone to do it for you?

[ro]

I am. However, I'm usually using hg with the hg-git extension and had trouble comitting this particular patch (connection closed by git server).

flang/tools/f18-parse-demo/CMakeLists.txt

 add_flang_tool(f18-parse-demo
   f18-parse-demo.cpp
   stub-evaluate.cpp
 )
 
 target_link_libraries(f18-parse-demo
   PRIVATE
+  FortranCommon
   FortranParser
   )

flang/tools/f18/CMakeLists.txt

 add_flang_tool(f18
   dump.cpp
   f18.cpp
 )
 
 target_link_libraries(f18
   PRIVATE
+  FortranCommon
   FortranParser
   FortranEvaluate
   FortranSemantics
   FortranLower
   LLVMSupport
 )
 
 set(MODULES

flang/unittests/Evaluate/CMakeLists.txt

 add_test(Leadz leading-zero-bit-count-test)
 add_test(PopPar bit-population-count-test)
 
 add_executable(expression-test
   expression.cpp
 )
 
 target_link_libraries(expression-test
+  FortranCommon
   FortranEvaluateTesting
   FortranEvaluate
   FortranSemantics
   FortranParser
   LLVMSupport
 )
 
 add_executable(integer-test
   integer.cpp
 )
 
 target_link_libraries(integer-test
   FortranEvaluateTesting
   FortranEvaluate
   FortranSemantics
   LLVMSupport
 )
 
 add_executable(intrinsics-test
   intrinsics.cpp
 )
 
 target_link_libraries(intrinsics-test
+  FortranCommon
   FortranEvaluateTesting
   FortranEvaluate
   FortranDecimal
   FortranSemantics
   FortranParser
   FortranRuntime
   LLVMSupport
 )
target_link_libraries(ISO-Fortran-binding-test
   LLVMSupport
 )
 
 add_executable(folding-test
   folding.cpp
 )
 
 target_link_libraries(folding-test
+  FortranCommon
   FortranEvaluateTesting
   FortranEvaluate
   FortranSemantics
   LLVMSupport
 )
 
 add_test(Expression expression-test)
 add_test(Integer integer-test)
 add_test(Intrinsics intrinsics-test)
 add_test(Logical logical-test)
 add_test(Real real-test)
 add_test(RESHAPE reshape-test)
 add_test(ISO-binding ISO-Fortran-binding-test)
 add_test(folding folding-test)