Closes Issue 17861: Autogenerate Include/opcode.h from opcode.py.

It includes required changes in Makefile.pre.in and configure.ac
among other files.

Tools/scripts/generate_opcode_h.py

@@ -0,0 +1,53 @@
+# This script generates the opcode.h header file.
+
+import sys
+if len(sys.argv) > 0:
+    sys.path.insert(0, sys.argv[1])
+# Importing module from our given src directory.
+import opcode
+header = """/* Auto-generated by Tools/scripts/generate_opcode_h.py */
+#ifndef Py_OPCODE_H
+#define Py_OPCODE_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+    /* Instruction opcodes for compiled code */
+"""
+
+footer = """
+/* EXCEPT_HANDLER is a special, implicit block type which is created when
+   entering an except handler. It is not an opcode but we define it here
+   as we want it to be available to both frameobject.c and ceval.c, while
+   remaining private.*/
+#define EXCEPT_HANDLER 257
+
+
+enum cmp_op {PyCmp_LT=Py_LT, PyCmp_LE=Py_LE, PyCmp_EQ=Py_EQ, PyCmp_NE=Py_NE,
+                PyCmp_GT=Py_GT, PyCmp_GE=Py_GE, PyCmp_IN, PyCmp_NOT_IN,
+                PyCmp_IS, PyCmp_IS_NOT, PyCmp_EXC_MATCH, PyCmp_BAD};
+
+#define HAS_ARG(op) ((op) >= HAVE_ARGUMENT)
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_OPCODE_H */
+"""
+
+
+def main(outfile='Include/opcode.h'):
+    with open(outfile, 'w') as fobj:
+        fobj.write(header)
+        for name in opcode.opname:
+            if name in opcode.opmap:
+                fobj.write("#define %-20s\t%-3s\n" % (name, opcode.opmap[name]))
+            if name == 'POP_EXCEPT': # Special entry for HAVE_ARGUMENT
+                fobj.write("#define %-20s\t%-3d\n" %
+                            ('HAVE_ARGUMENT', opcode.HAVE_ARGUMENT))
+        fobj.write(footer)
+
+
+if __name__ == '__main__':
+    main(sys.argv[2])