Issue #16714: use 'raise' exceptions, don't 'throw'.

Patch by Serhiy Storchaka.

Modules/_io/_iomodule.c

@@ -59,7 +59,7 @@ PyDoc_STRVAR(module_doc,
 "At the top of the I/O hierarchy is the abstract base class IOBase. It\n"
 "defines the basic interface to a stream. Note, however, that there is no\n"
 "separation between reading and writing to streams; implementations are\n"
-"allowed to throw an IOError if they do not support a given operation.\n"
+"allowed to raise an IOError if they do not support a given operation.\n"
 "\n"
 "Extending IOBase is RawIOBase which deals simply with the reading and\n"
 "writing of raw bytes to a stream. FileIO subclasses RawIOBase to provide\n"

Modules/parsermodule.c

@@ -718,7 +718,7 @@ parser_tuple2st(PyST_Object *self, PyObject *args, PyObject *kw)
             err_string("parse tree does not use a valid start symbol");
         }
     }
-    /*  Make sure we throw an exception on all errors.  We should never
+    /*  Make sure we raise an exception on all errors.  We should never
      *  get this, but we'd do well to be sure something is done.
      */
     if (st == NULL && !PyErr_Occurred())
@@ -824,7 +824,7 @@ build_node_children(PyObject *tuple, node *root, int *line_num)
         else if (!ISNONTERMINAL(type)) {
             /*
              *  It has to be one or the other; this is an error.
-             *  Throw an exception.
+             *  Raise an exception.
              */
             PyObject *err = Py_BuildValue("os", elem, "unknown node type.");
             PyErr_SetObject(parser_error, err);
@@ -876,7 +876,7 @@ build_node_tree(PyObject *tuple)
     if (ISTERMINAL(num)) {
         /*
          *  The tuple is simple, but it doesn't start with a start symbol.
-         *  Throw an exception now and be done with it.
+         *  Raise an exception now and be done with it.
          */
         tuple = Py_BuildValue("os", tuple,
                     "Illegal syntax-tree; cannot start with terminal symbol.");

Modules/posixmodule.c

@@ -349,7 +349,7 @@ static int win32_can_symlink = 0;
 
 #if defined _MSC_VER && _MSC_VER >= 1400
 /* Microsoft CRT in VS2005 and higher will verify that a filehandle is
- * valid and throw an assertion if it isn't.
+ * valid and raise an assertion if it isn't.
  * Normally, an invalid fd is likely to be a C program error and therefore
  * an assertion can be useful, but it does contradict the POSIX standard
  * which for write(2) states: