delete std::variants when we're done with them

Author: Radvendii

src/libexpr/parser.y

@@ -311,6 +311,7 @@ expr_simple
           [&](std::string_view str) { $$ = new ExprString(state->alloc, str); },
           [&](Expr * expr) { $$ = expr; }},
       *$2);
+      delete $2;
   }
   | IND_STRING_OPEN ind_string_parts IND_STRING_CLOSE {
       $$ = state->stripIndentation(CUR_POS, std::move(*$2));
@@ -471,6 +472,7 @@ attrs
               });
           }
       }, *$2);
+      delete $2;
     }
   | { $$ = new std::vector<std::pair<AttrName, PosIdx>>; }
   ;
@@ -483,6 +485,7 @@ attrpath
           [&](std::string_view str) { $$->push_back(AttrName(state->symbols.create(str))); },
           [&](Expr * expr) { $$->push_back(AttrName(expr)); }
       }, *$3);
+      delete $3;
     }
   | attr { $$ = new std::vector<AttrName>; $$->push_back(AttrName(state->symbols.create($1))); }
   | string_attr
@@ -491,6 +494,7 @@ attrpath
           [&](std::string_view str) { $$->push_back(AttrName(state->symbols.create(str))); },
           [&](Expr * expr) { $$->push_back(AttrName(expr)); }
       }, *$1);
+      delete $1;
     }
   ;