[flang][OpenMP] Remove `OmpEndLoopDirective` handles from code.

This directive is currently lowered as NOP.

Patch is an attempt upstream code from:
PR: https://github.com/flang-compiler/f18-llvm-project/pull/573

Reviewed By: kiranchandramohan, schweitz, clementval

Differential Revision: https://reviews.llvm.org/D100576

GitOrigin-RevId: 5064a34165ccadf4718b2c159eff41f008261681
diff --git a/include/flang/Lower/OpenMP.h b/include/flang/Lower/OpenMP.h
index 13dd43b..a056443 100644
--- a/include/flang/Lower/OpenMP.h
+++ b/include/flang/Lower/OpenMP.h
@@ -16,7 +16,6 @@
 namespace Fortran {
 namespace parser {
 struct OpenMPConstruct;
-struct OmpEndLoopDirective;
 } // namespace parser
 
 namespace lower {
@@ -30,9 +29,6 @@
 void genOpenMPConstruct(AbstractConverter &, pft::Evaluation &,
                         const parser::OpenMPConstruct &);
 
-void genOpenMPEndLoop(AbstractConverter &, pft::Evaluation &,
-                      const parser::OmpEndLoopDirective &);
-
 } // namespace lower
 } // namespace Fortran
 
diff --git a/lib/Lower/OpenMP.cpp b/lib/Lower/OpenMP.cpp
index 4bff1cd..36c5ebe 100644
--- a/lib/Lower/OpenMP.cpp
+++ b/lib/Lower/OpenMP.cpp
@@ -286,10 +286,3 @@
       },
       ompConstruct.u);
 }
-
-void Fortran::lower::genOpenMPEndLoop(
-    Fortran::lower::AbstractConverter &converter,
-    Fortran::lower::pft::Evaluation &,
-    const Fortran::parser::OmpEndLoopDirective &) {
-  TODO(converter.getCurrentLocation(), "OmpEndLoopDirective");
-}