Merge pull request #619 from JuliaSymbolics/b/Code-maketerm

Import `maketerm` in SymbolicUtils.Code to resolve `UndefVarError`

Author: bowenszhu

src/code.jl

@@ -9,7 +9,7 @@ export toexpr, Assignment, (←), Let, Func, DestructuredArgs, LiteralExpr,
 import ..SymbolicUtils
 import ..SymbolicUtils.Rewriters
 import SymbolicUtils: @matchable, BasicSymbolic, Sym, Term, iscall, operation, arguments, issym,
-                      symtype, similarterm, unsorted_arguments, metadata, isterm, term
+                      symtype, similarterm, unsorted_arguments, metadata, isterm, term, maketerm
 
 ##== state management ==##