[clang][Diagnostics] Provide source range to invalid casts in const expr

[tbaeder]

Ping

[cor3ntin]

LGTM (modulo failed build / rebase)

clang/lib/AST/ExprConstant.cpp

case CK_IntegralCast: {
     }
 
     return Success(HandleIntToIntCast(Info, E, DestType, SrcType,
                                       Result.getInt()), E);
   }
 
   case CK_PointerToIntegral: {
     CCEDiag(E, diag::note_constexpr_invalid_cast)
-        << 2 << Info.Ctx.getLangOpts().CPlusPlus;
+        << 2 << Info.Ctx.getLangOpts().CPlusPlus << E->getSourceRange();
 
     LValue LV;
     if (!EvaluatePointer(SubExpr, LV, Info))
       return false;
 
     if (LV.getLValueBase()) {
       // Only allow based lvalue casts if they are lossless.
       // FIXME: Allow a larger integer size than the pointer size, and allow

clang/lib/AST/Interp/Interp.cpp

 
 bool CheckPotentialReinterpretCast(InterpState &S, CodePtr OpPC,
                                    const Pointer &Ptr) {
   if (!S.inConstantContext())
     return true;
 
   const SourceInfo &E = S.Current->getSource(OpPC);
   S.CCEDiag(E, diag::note_constexpr_invalid_cast)
-      << 2 << S.getLangOpts().CPlusPlus;
+      << 2 << S.getLangOpts().CPlusPlus << S.Current->getRange(OpPC);
   return false;
 }
 
 bool CastFP(InterpState &S, CodePtr OpPC, const llvm::fltSemantics *Sem,
             llvm::RoundingMode RM) {
   Floating F = S.Stk.pop<Floating>();
   Floating Result = F.toSemantics(Sem, RM);
   S.Stk.push<Floating>(Result);

clang/test/Misc/constexpr-source-ranges.cpp

 // RUN: not %clang_cc1 -fsyntax-only -fdiagnostics-print-source-range-info -fcxx-exceptions %s 2>&1 | FileCheck %s
 // RUN: not %clang_cc1 -fsyntax-only -fexperimental-new-constant-interpreter -fdiagnostics-print-source-range-info -fcxx-exceptions %s 2>&1 | FileCheck %s
 
 constexpr int f() {
   throw 1;
   return 0;
 }
 
 // CHECK: constexpr-source-ranges.cpp:5:3:{5:3-5:10}
+
+
+constexpr int I = 12;
+constexpr const int *P = &I;
+constexpr long L = (long)P;
+// CHECK: constexpr-source-ranges.cpp:14:20:{14:20-14:27}