[flang] Fix missing CGPasses.h.inc (#71691)

I could reproduce using unix makefiles with -j1 option, with version
16.0.6
Closes #61543
Closes #57680

Author: jschueller

flang/lib/Frontend/CMakeLists.txt

@@ -15,6 +15,7 @@ add_flang_library(flangFrontend
 
   DEPENDS
   FIRDialect
+  FIROptCodeGenPassIncGen
   FIROptTransformsPassIncGen
   HLFIRDialect
   MLIRIR