[polly] Drop const from return types (NFC) (#140837)

Author: kazutakahirata

polly/include/polly/CodeGen/IslNodeBuilder.h

@@ -112,7 +112,7 @@ class IslNodeBuilder {
   BlockGenerator &getBlockGenerator() { return BlockGen; }
 
   /// Return the parallel subfunctions that have been created.
-  const ArrayRef<Function *> getParallelSubfunctions() const {
+  ArrayRef<Function *> getParallelSubfunctions() const {
     return ParallelSubfunctions;
   }
 

polly/include/polly/ScopInfo.h

@@ -855,10 +855,10 @@ class MemoryAccess final {
   }
 
   /// Return a string representation of the access's reduction type.
-  const std::string getReductionOperatorStr() const;
+  std::string getReductionOperatorStr() const;
 
   /// Return a string representation of the reduction type @p RT.
-  static const std::string getReductionOperatorStr(ReductionType RT);
+  static std::string getReductionOperatorStr(ReductionType RT);
 
   /// Return the element type of the accessed array wrt. this access.
   Type *getElementType() const { return ElementType; }

polly/lib/Analysis/ScopInfo.cpp

@@ -527,7 +527,7 @@ void MemoryAccess::updateDimensionality() {
   }
 }
 
-const std::string
+std::string
 MemoryAccess::getReductionOperatorStr(MemoryAccess::ReductionType RT) {
   switch (RT) {
   case MemoryAccess::RT_NONE:
@@ -910,7 +910,7 @@ void MemoryAccess::realignParams() {
   AccessRelation = AccessRelation.align_params(CtxSpace);
 }
 
-const std::string MemoryAccess::getReductionOperatorStr() const {
+std::string MemoryAccess::getReductionOperatorStr() const {
   return MemoryAccess::getReductionOperatorStr(getReductionType());
 }
 

polly/lib/CodeGen/IslAst.cpp

@@ -134,7 +134,7 @@ static isl_printer *printLine(__isl_take isl_printer *Printer,
 }
 
 /// Return all broken reductions as a string of clauses (OpenMP style).
-static const std::string getBrokenReductionsStr(const isl::ast_node &Node) {
+static std::string getBrokenReductionsStr(const isl::ast_node &Node) {
   IslAstInfo::MemoryAccessSet *BrokenReductions;
   std::string str;