[flang] Add missing dependency on tablegen files

This issue was raised on llvm#64268.

`flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp` includes
`flang/Optimizer/HLFIR/HLFIRDialect.h` and might fails if the HLFIR related
tablegen files have not been generated.

Reviewed By: vzakhari

Differential Revision: https://reviews.llvm.org/D156751

Author: clementval

flang/lib/Optimizer/Transforms/CMakeLists.txt

@@ -23,6 +23,7 @@ add_flang_library(FIRTransforms
   DEPENDS
   FIRDialect
   FIROptTransformsPassIncGen
+  HLFIROpsIncGen
 
   LINK_LIBS
   FIRBuilder