build: add file dependencies for gyb

Add dependencies on the files for gyb to ensure that updates gyb are
treated as triggers to regenerate the files.  This is suspected to have
caused issues for incremental builds.

Author: compnerd

cmake/modules/AddSwift.cmake

@@ -5,6 +5,18 @@ include(SwiftWindowsSupport)
 include(SwiftAndroidSupport)
 
 function(_swift_gyb_target_sources target scope)
+  file(GLOB GYB_UNICODE_DATA ${SWIFT_SOURCE_DIR}/utils/UnicodeData/*)
+  file(GLOB GYB_STDLIB_SUPPORT ${SWIFT_SOURCE_DIR}/utils/gyb_stdlib_support.py)
+  file(GLOB GYB_SYNTAX_SUPPORT ${SWIFT_SOURCE_DIR}/utils/gyb_syntax_support/*)
+  file(GLOB GYB_SOURCEKIT_SUPPORT ${SWIFT_SOURCE_DIR}/utils/gyb_sourcekit_support/*)
+  set(GYB_SOURCES
+    ${SWIFT_SOURCE_DIR}/utils/GYBUnicodeDataUtils.py
+    ${SWIFT_SOURCE_DIR}/utils/SwiftIntTypes.py
+    ${GYB_UNICODE_DATA}
+    ${GYB_STDLIB_SUPPORT}
+    ${GYB_SYNTAX_SUPPORT}
+    ${GYB_SOURCEKIT_SUPPORT})
+
   foreach(source ${ARGN})
     get_filename_component(generated ${source} NAME_WLE)
     get_filename_component(absolute ${source} REALPATH)
@@ -17,6 +29,7 @@ function(_swift_gyb_target_sources target scope)
       COMMAND
         ${CMAKE_COMMAND} -E remove ${CMAKE_CURRENT_BINARY_DIR}/${generated}.tmp
       DEPENDS
+        ${GYB_SOURCES}
         ${absolute})
     set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/${generated} PROPERTIES
       GENERATED TRUE)