Fix bug with binop assignment typechecking

src/typechecker.cpp

@@ -99,6 +99,8 @@ namespace AST {
         auto rhs_ty = this->m_rhs->typecheck(state, scope, {});
 
         if (this->m_binop == types::BinOp::Assignment) {
+            // Re-typecheck rhs to actually match lhs
+            auto rhs_ty = this->m_rhs->typecheck(state, scope, lhs_ty);
             return lhs_ty;
         }
 

test.c

@@ -9,5 +9,6 @@ int fibonacci(int n) {
 int main() {
     printf("10th fibonacci number is %d!", fibonacci(10));
     char res = 0;
+    res = 15;
     return (int)res;
 }