Embarcadero,OpenWatcom: Clear unused flags for creating shared libraries

Clear `CMAKE_SHARED_LIBRARY_CREATE_<LANG>_FLAGS` since no special
link flags are needed to create a DLL with these toolchains.
Our shared library creation rules do not reference the placeholder,
so this variable was never used.  However, we may soon teach the
generators to look it up directly.

Modules/Compiler/OpenWatcom.cmake

@@ -75,12 +75,16 @@ set(CMAKE_C_CREATE_SHARED_LIBRARY
   "<CMAKE_LINKER> ${CMAKE_WLINK_QUIET} name <TARGET> <LINK_FLAGS> option implib=<TARGET_IMPLIB> file {<OBJECTS>} <LINK_LIBRARIES>")
 # C++ create a shared library
 set(CMAKE_CXX_CREATE_SHARED_LIBRARY ${CMAKE_C_CREATE_SHARED_LIBRARY})
+set(CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS "")
+set(CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS "")
 
 # C create a shared module
 set(CMAKE_C_CREATE_SHARED_MODULE
   "<CMAKE_LINKER> ${CMAKE_WLINK_QUIET} name <TARGET> <LINK_FLAGS> file {<OBJECTS>} <LINK_LIBRARIES>")
 # C++ create a shared module
 set(CMAKE_CXX_CREATE_SHARED_MODULE ${CMAKE_C_CREATE_SHARED_MODULE})
+set(CMAKE_SHARED_MODULE_CREATE_C_FLAGS "")
+set(CMAKE_SHARED_MODULE_CREATE_CXX_FLAGS "")
 
 # C create a static library
 set(CMAKE_C_CREATE_STATIC_LIBRARY

Modules/Platform/Windows-Embarcadero.cmake

@@ -74,6 +74,8 @@ endif()
 macro(__embarcadero_language lang)
   set(CMAKE_${lang}_COMPILE_OPTIONS_DLL "${_tD}") # Note: This variable is a ';' separated list
   set(CMAKE_SHARED_LIBRARY_${lang}_FLAGS "${_tD}") # ... while this is a space separated string.
+  set(CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS "")
+  set(CMAKE_SHARED_MODULE_CREATE_${lang}_FLAGS "")
   set(CMAKE_${lang}_USE_RESPONSE_FILE_FOR_INCLUDES 1)
 
   set (CMAKE_${lang}_LINKER_WRAPPER_FLAG "-l")