fix the thrift CMake rules to add dependencies on the thrift compiler

Summary:
Update the thrift C++ and Python CMake rules to indicate that the output also
depends on the thrift compiler itself.

Previously the C++ rule indicated that the output depended on the thrift
template files, which caught most cases when the thrift compiler was updated,
but wasn't fully correct.  The thrift templates were also removed and baked
into the thrift compiler binary in D16356056.

Reviewed By: yfeldblum, chadaustin

Differential Revision: D17401217

fbshipit-source-id: ae5cde7a7e5e07a74406a1b6f4469124187bc12f

build/fbcode_builder/CMake/FBThriftCppLibrary.cmake

@@ -121,7 +121,7 @@ function(add_fbthrift_cpp_library LIB_NAME THRIFT_FILE)
       "${THRIFT_FILE}"
     DEPENDS
       ${ARG_DEPENDS}
-      ${THRIFT_TEMPLATE_FILES}
+      "${FBTHRIFT_COMPILER}"
   )
 
   # Now emit the library rule to compile the sources

build/fbcode_builder/CMake/FBThriftPyLibrary.cmake

@@ -93,6 +93,8 @@ function(add_fbthrift_py_library LIB_NAME THRIFT_FILE)
       "${CMAKE_BINARY_DIR}"
     MAIN_DEPENDENCY
       "${THRIFT_FILE}"
+    DEPENDS
+      "${FBTHRIFT_COMPILER}"
   )
 
   # We always want to pass the namespace as "" to this call: