Revert "[flang][OpenMP] Decompose compound constructs, do recursive lowering (#90098)"

It breaks some builds, e.g.
https://lab.llvm.org/buildbot/#/builders/268/builds/13909

This reverts commit ca1bd59.

Author: kparzysz

flang/lib/Lower/CMakeLists.txt

@@ -27,7 +27,6 @@ add_flang_library(FortranLower
   OpenMP/ClauseProcessor.cpp
   OpenMP/Clauses.cpp
   OpenMP/DataSharingProcessor.cpp
-  OpenMP/Decomposer.cpp
   OpenMP/OpenMP.cpp
   OpenMP/ReductionProcessor.cpp
   OpenMP/Utils.cpp

flang/lib/Lower/OpenMP/Clauses.cpp

@@ -1227,27 +1227,4 @@ List<Clause> makeClauses(const parser::OmpClauseList &clauses,
     return makeClause(s, semaCtx);
   });
 }
-
-bool transferLocations(const List<Clause> &from, List<Clause> &to) {
-  bool allDone = true;
-
-  for (Clause &clause : to) {
-    if (!clause.source.empty())
-      continue;
-    auto found =
-        llvm::find_if(from, [&](const Clause &c) { return c.id == clause.id; });
-    // This is not completely accurate, but should be good enough for now.
-    // It can be improved in the future if necessary, but in cases of
-    // synthesized clauses getting accurate location may be impossible.
-    if (found != from.end()) {
-      clause.source = found->source;
-    } else {
-      // Found a clause that won't have "source".
-      allDone = false;
-    }
-  }
-
-  return allDone;
-}
-
 } // namespace Fortran::lower::omp

flang/lib/Lower/OpenMP/Clauses.h

@@ -23,15 +23,11 @@
 
 namespace Fortran::lower::omp {
 using namespace Fortran;
+using SomeType = evaluate::SomeType;
 using SomeExpr = semantics::SomeExpr;
 using MaybeExpr = semantics::MaybeExpr;
 
-// evaluate::SomeType doesn't provide == operation. It's not really used in
-// flang's clauses so far, so a trivial implementation is sufficient.
-struct TypeTy : public evaluate::SomeType {
-  bool operator==(const TypeTy &t) const { return true; }
-};
-
+using TypeTy = SomeType;
 using IdTy = semantics::Symbol *;
 using ExprTy = SomeExpr;
 
@@ -226,8 +222,6 @@ using When = tomp::clause::WhenT<TypeTy, IdTy, ExprTy>;
 using Write = tomp::clause::WriteT<TypeTy, IdTy, ExprTy>;
 } // namespace clause
 
-using tomp::type::operator==;
-
 struct CancellationConstructType {
   using EmptyTrait = std::true_type;
 };
@@ -250,7 +244,6 @@ using ClauseBase = tomp::ClauseT<TypeTy, IdTy, ExprTy,
                                  MemoryOrder, Threadprivate>;
 
 struct Clause : public ClauseBase {
-  // "source" will be ignored by tomp::type::operator==.
   parser::CharBlock source;
 };
 
@@ -265,8 +258,6 @@ Clause makeClause(const Fortran::parser::OmpClause &cls,
 
 List<Clause> makeClauses(const parser::OmpClauseList &clauses,
                          semantics::SemanticsContext &semaCtx);
-
-bool transferLocations(const List<Clause> &from, List<Clause> &to);
 } // namespace Fortran::lower::omp
 
 #endif // FORTRAN_LOWER_OPENMP_CLAUSES_H