Revert "[clang][Interp] Implement C++ Range-for loops"

This reverts commit bce8b3c183.

This commit breaks memory-sanitizer builds:
https://lab.llvm.org/buildbot/#/builders/5/builds/31899

clang/lib/AST/Interp/ByteCodeStmtGen.cpp

@@ -172,8 +172,6 @@ bool ByteCodeStmtGen<Emitter>::visitStmt(const Stmt *S) {
     return visitDoStmt(cast<DoStmt>(S));
   case Stmt::ForStmtClass:
     return visitForStmt(cast<ForStmt>(S));
-  case Stmt::CXXForRangeStmtClass:
-    return visitCXXForRangeStmt(cast<CXXForRangeStmt>(S));
   case Stmt::BreakStmtClass:
     return visitBreakStmt(cast<BreakStmt>(S));
   case Stmt::ContinueStmtClass:
@@ -371,56 +369,6 @@ bool ByteCodeStmtGen<Emitter>::visitForStmt(const ForStmt *S) {
   return true;
 }
 
-template <class Emitter>
-bool ByteCodeStmtGen<Emitter>::visitCXXForRangeStmt(const CXXForRangeStmt *S) {
-  const Stmt *Init = S->getInit();
-  const Expr *Cond = S->getCond();
-  const Expr *Inc = S->getInc();
-  const Stmt *Body = S->getBody();
-  const Stmt *BeginStmt = S->getBeginStmt();
-  const Stmt *RangeStmt = S->getRangeStmt();
-  const Stmt *EndStmt = S->getEndStmt();
-  const VarDecl *LoopVar = S->getLoopVariable();
-
-  LabelTy EndLabel = this->getLabel();
-  LabelTy CondLabel = this->getLabel();
-  LabelTy IncLabel = this->getLabel();
-  ExprScope<Emitter> ES(this);
-  LoopScope<Emitter> LS(this, EndLabel, IncLabel);
-
-  // Emit declarations needed in the loop.
-  if (Init && !this->visitStmt(Init))
-    return false;
-  if (!this->visitStmt(RangeStmt))
-    return false;
-  if (!this->visitStmt(BeginStmt))
-    return false;
-  if (!this->visitStmt(EndStmt))
-    return false;
-
-  // Now the condition as well as the loop variable assignment.
-  this->emitLabel(CondLabel);
-  if (!this->visitBool(Cond))
-    return false;
-  if (!this->jumpFalse(EndLabel))
-    return false;
-
-  if (!this->visitVarDecl(LoopVar))
-    return false;
-
-  // Body.
-  if (!this->visitStmt(Body))
-    return false;
-  this->emitLabel(IncLabel);
-  if (!this->discard(Inc))
-    return false;
-  if (!this->jump(CondLabel))
-    return false;
-
-  this->emitLabel(EndLabel);
-  return true;
-}
-
 template <class Emitter>
 bool ByteCodeStmtGen<Emitter>::visitBreakStmt(const BreakStmt *S) {
   if (!BreakLabel)

clang/lib/AST/Interp/ByteCodeStmtGen.h

@@ -60,7 +60,6 @@ private:
   bool visitWhileStmt(const WhileStmt *S);
   bool visitDoStmt(const DoStmt *S);
   bool visitForStmt(const ForStmt *S);
-  bool visitCXXForRangeStmt(const CXXForRangeStmt *S);
   bool visitBreakStmt(const BreakStmt *S);
   bool visitContinueStmt(const ContinueStmt *S);
   bool visitSwitchStmt(const SwitchStmt *S);

clang/test/AST/Interp/loops.cpp

@@ -3,6 +3,10 @@
 // RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++20 -verify=expected-cpp20 %s
 // RUN: %clang_cc1 -std=c++20 -verify=ref %s
 
+// ref-no-diagnostics
+// expected-no-diagnostics
+// expected-cpp20-no-diagnostics
+
 namespace WhileLoop {
   constexpr int f() {
     int i = 0;
@@ -270,57 +274,3 @@ namespace ForLoop {
 #endif
 
 };
-
-namespace RangeForLoop {
-  constexpr int localArray() {
-    int a[] = {1,2,3,4};
-    int s = 0;
-    for(int i : a) {
-      s += i;
-    }
-    return s;
-  }
-  static_assert(localArray() == 10, "");
-
-  constexpr int localArray2() {
-    int a[] = {1,2,3,4};
-    int s = 0;
-    for(const int &i : a) {
-      s += i;
-    }
-    return s;
-  }
-  static_assert(localArray2() == 10, "");
-
-  constexpr int nested() {
-    int s = 0;
-    for (const int i : (int[]){1,2,3,4}) {
-      int a[] = {i, i};
-      for(int m : a) {
-        s += m;
-      }
-    }
-    return s;
-  }
-  static_assert(nested() == 20, "");
-
-  constexpr int withBreak() {
-    int s = 0;
-    for (const int &i: (bool[]){false, true}) {
-      if (i)
-        break;
-      s++;
-    }
-    return s;
-  }
-  static_assert(withBreak() == 1, "");
-
-  constexpr void NoBody() {
-    for (const int &i: (bool[]){false, true}); // expected-warning {{empty body}} \
-                                               // expected-note {{semicolon on a separate line}} \
-                                               // expected-cpp20-warning {{empty body}} \
-                                               // expected-cpp20-note {{semicolon on a separate line}} \
-                                               // ref-warning {{empty body}} \
-                                               // ref-note {{semicolon on a separate line}}
-  }
-}