ENH: Enabled preprocessor make rules for Watcom.

Modules/Platform/Windows-wcl386.cmake

@@ -42,6 +42,14 @@ SET(CMAKE_CXX_COMPILE_OBJECT
 SET(CMAKE_C_COMPILE_OBJECT
     "<CMAKE_C_COMPILER> ${CMAKE_START_TEMP_FILE} ${CMAKE_WCL_QUIET} <FLAGS>  -dWIN32 -fo<OBJECT>   -c -cc <SOURCE>${CMAKE_END_TEMP_FILE}")
 
+# preprocess a C source file
+SET(CMAKE_C_CREATE_PREPROCESSED_SOURCE
+    "<CMAKE_C_COMPILER> ${CMAKE_START_TEMP_FILE} ${CMAKE_WCL_QUIET} <FLAGS> -dWIN32 -fo<PREPROCESSED_SOURCE> -pl -cc <SOURCE>${CMAKE_END_TEMP_FILE}")
+
+# preprocess a C++ source file
+SET(CMAKE_CXX_CREATE_PREPROCESSED_SOURCE
+    "<CMAKE_CXX_COMPILER> ${CMAKE_START_TEMP_FILE} ${CMAKE_WCL_QUIET} <FLAGS> -dWIN32 -fo<PREPROCESSED_SOURCE> -pl -cc++ <SOURCE>${CMAKE_END_TEMP_FILE}")
+
 SET(CMAKE_CXX_CREATE_SHARED_MODULE
  "wlink ${CMAKE_START_TEMP_FILE} system nt_dll  ${CMAKE_WLINK_QUIET} name <TARGET> option caseexact  file {<OBJECTS>} <LINK_LIBRARIES> ${CMAKE_END_TEMP_FILE}")
 SET(CMAKE_CXX_CREATE_SHARED_LIBRARY