Use PyTruffleUnicode_FromUCS for _PyUnicode_FromUCS1/2/4

Author: fangerer

graalpython/com.oracle.graal.python.cext/src/unicodeobject.c

@@ -369,21 +369,17 @@ PyObject * PyUnicode_FromWideChar(const wchar_t *u, Py_ssize_t size) {
 }
 
 static PyObject* _PyUnicode_FromUCS1(const Py_UCS1* u, Py_ssize_t size) {
-	Py_UCS1* buffer = (Py_UCS1*) malloc(size * PyUnicode_1BYTE_KIND);
-	memcpy(buffer, u, size * PyUnicode_1BYTE_KIND);
-    return GraalPyTruffleUnicode_New(polyglot_from_Py_UCS1_array(buffer, size), PyUnicode_1BYTE_KIND, 0);
+    return GraalPyTruffleUnicode_FromUCS(polyglot_from_i8_array((int8_t *)u, size), size, PyUnicode_1BYTE_KIND);
 }
 
 static PyObject* _PyUnicode_FromUCS2(const Py_UCS2 *u, Py_ssize_t size) {
-	Py_UCS2* buffer = (Py_UCS2*) malloc(size * PyUnicode_2BYTE_KIND);
-	memcpy(buffer, u, size * PyUnicode_2BYTE_KIND);
-    return GraalPyTruffleUnicode_New(polyglot_from_Py_UCS2_array(buffer, size), PyUnicode_2BYTE_KIND, 0);
+    const Py_ssize_t byte_size = size * PyUnicode_2BYTE_KIND;
+    return GraalPyTruffleUnicode_FromUCS(polyglot_from_i8_array((int8_t *)u, byte_size), byte_size, PyUnicode_2BYTE_KIND);
 }
 
 static PyObject* _PyUnicode_FromUCS4(const Py_UCS4 *u, Py_ssize_t size) {
-	Py_UCS4* buffer = (Py_UCS4*) malloc(size * PyUnicode_4BYTE_KIND);
-	memcpy(buffer, u, size * PyUnicode_4BYTE_KIND);
-    return GraalPyTruffleUnicode_New(polyglot_from_Py_UCS4_array(buffer, size), PyUnicode_4BYTE_KIND, 0);
+    const Py_ssize_t byte_size = size * PyUnicode_4BYTE_KIND;
+    return GraalPyTruffleUnicode_FromUCS(polyglot_from_i8_array((int8_t *)u, byte_size), byte_size, PyUnicode_4BYTE_KIND);
 }
 
 // taken from CPython "Python/Objects/unicodeobject.c"