Remove toDataLengthPair from character helper

This is a legacy function, it was kept to protect from array character in
context that are not array ready. It fired in createUnboxChar where it is
OK to get arrays. Remove it and enforce the arrays bans on caller sides
where it make sens.

Author: jeanPerier

flang/include/flang/Lower/CharacterExpr.h

@@ -68,7 +68,7 @@ class CharacterExprHelper {
                                       const fir::CharBoxValue &rhs);
 
   /// LEN_TRIM intrinsic.
-  mlir::Value createLenTrim(mlir::Value str);
+  mlir::Value createLenTrim(const fir::CharBoxValue &str);
 
   /// Embox \p addr and \p len and return fir.boxchar.
   /// Take care of type conversions before emboxing.
@@ -163,7 +163,6 @@ class CharacterExprHelper {
   /// FIXME: the implementation also needs a clean-up now that
   /// CharBoxValue are better propagated.
   fir::CharBoxValue materializeValue(mlir::Value str);
-  fir::CharBoxValue toDataLengthPair(mlir::Value character);
   mlir::Type getReferenceType(const fir::CharBoxValue &c) const;
   mlir::Type getReferenceType(mlir::Value str) const;
   mlir::Type getSeqTy(const fir::CharBoxValue &c) const;
@@ -174,7 +173,6 @@ class CharacterExprHelper {
   void createLengthOneAssign(const fir::CharBoxValue &lhs,
                              const fir::CharBoxValue &rhs);
   void createAssign(const fir::CharBoxValue &lhs, const fir::CharBoxValue &rhs);
-  mlir::Value createLenTrim(const fir::CharBoxValue &str);
   mlir::Value createBlankConstantCode(fir::CharacterType type);
 
 private:

flang/lib/Lower/CharacterExpr.cpp

@@ -632,20 +632,3 @@ Fortran::lower::CharacterExprHelper::readLengthFromBox(mlir::Value box) {
   }
   return size;
 }
-
-bool Fortran::lower::CharacterExprHelper::hasConstantLengthInType(
-    const fir::ExtendedValue &exv) {
-  auto type = fir::getBase(exv).getType();
-  if (auto boxTy = type.dyn_cast<fir::BoxType>())
-    type = boxTy.getEleTy();
-  if (auto eleTy = fir::dyn_cast_ptrEleTy(type))
-    type = eleTy;
-  if (auto seqTy = type.dyn_cast<fir::SequenceType>()) {
-    assert(seqTy.getEleTy().isa<fir::CharacterType>() &&
-           "entity is not a character");
-    assert(seqTy.getShape().size() > 0 && "character has empty shape");
-    auto lenVal = seqTy.getShape()[0];
-    return lenVal != fir::SequenceType::getUnknownExtent();
-  }
-  return false;
-}