Use an AST_Str for IMPORT_FROM instead of an AST_Name

Also fix a GCC warning... not sure if this is supposed to be better though.

src/codegen/irgen/irgenerator.cpp

@@ -414,13 +414,13 @@ private:
             case AST_LangPrimitive::IMPORT_FROM: {
                 assert(node->args.size() == 2);
                 assert(node->args[0]->type == AST_TYPE::Name);
-                assert(node->args[1]->type == AST_TYPE::Name);
+                assert(node->args[1]->type == AST_TYPE::Str);
 
                 CompilerVariable* module = evalExpr(node->args[0], exc_info);
                 ConcreteCompilerVariable* converted_module = module->makeConverted(emitter, module->getBoxType());
                 module->decvref(emitter);
 
-                const std::string& name = ast_cast<AST_Name>(node->args[1])->id;
+                const std::string& name = ast_cast<AST_Str>(node->args[1])->s;
                 assert(name.size());
 
                 llvm::Value* r = emitter.createCall2(exc_info, g.funcs.importFrom, converted_module->getValue(),

src/core/cfg.cpp

@@ -1129,7 +1129,7 @@ public:
                 import_from->lineno = node->lineno;
                 import_from->col_offset = node->col_offset;
                 import_from->args.push_back(makeName(tmp_module_name, AST_TYPE::Load));
-                import_from->args.push_back(makeName(a->name, AST_TYPE::Load));
+                import_from->args.push_back(new AST_Str(a->name));
 
                 std::string tmp_import_name = nodeName(a);
                 pushAssign(tmp_import_name, import_from);

src/runtime/long.cpp

@@ -669,8 +669,12 @@ Box* longHash(BoxedLong* self) {
 
     // Not sure if this is a good hash function or not;
     // simple, but only includes top bits:
-    double d = mpz_get_d(self->n);
-    return boxInt(*reinterpret_cast<int64_t*>(&d));
+    union {
+        uint64_t n;
+        double d;
+    };
+    d = mpz_get_d(self->n);
+    return boxInt(n);
 }
 
 void setupLong() {