[clang][Interp][NFC] Fix allocateLocalPrimitive parameter name

This is passed on to Program::createDescriptor, where it is used as a
value for IsConst.

Author: tbaederr

clang/lib/AST/Interp/ByteCodeExprGen.cpp

@@ -831,7 +831,7 @@ bool ByteCodeExprGen<Emitter>::VisitMaterializeTemporaryExpr(
   // For everyhing else, use local variables.
   if (SubExprT) {
     if (std::optional<unsigned> LocalIndex = allocateLocalPrimitive(
-            SubExpr, *SubExprT, /*IsMutable=*/true, /*IsExtended=*/true)) {
+            SubExpr, *SubExprT, /*IsConst=*/true, /*IsExtended=*/true)) {
       if (!this->visitInitializer(SubExpr))
         return false;
       this->emitSetLocal(*SubExprT, *LocalIndex, E);

clang/lib/AST/Interp/ByteCodeExprGen.h

@@ -185,7 +185,7 @@ class ByteCodeExprGen : public ConstStmtVisitor<ByteCodeExprGen<Emitter>, bool>,
                         llvm::function_ref<bool(const Expr *)> V);
 
   /// Creates a local primitive value.
-  unsigned allocateLocalPrimitive(DeclTy &&Decl, PrimType Ty, bool IsMutable,
+  unsigned allocateLocalPrimitive(DeclTy &&Decl, PrimType Ty, bool IsConst,
                                   bool IsExtended = false);
 
   /// Allocates a space storing a local given its type.