GH-128914: Remove all but one conditional stack effects (GH-129226)

* Remove all 'if (0)' and 'if (1)' conditional stack effects

* Use array instead of conditional for BUILD_SLICE args

* Refactor LOAD_GLOBAL to use a common conditional uop

* Remove conditional stack effects from LOAD_ATTR specializations

* Replace conditional stack effects in LOAD_ATTR with a 0 or 1 sized array.

* Remove conditional stack effects from CALL_FUNCTION_EX

Author: markshannon

Include/internal/pycore_magic_number.h

@@ -267,6 +267,7 @@ Known values:
     Python 3.14a4 3612 (Add POP_ITER and INSTRUMENTED_POP_ITER)
     Python 3.14a4 3613 (Add LOAD_CONST_MORTAL instruction)
     Python 3.14a5 3614 (Add BINARY_OP_EXTEND)
+    Python 3.14a5 3615 (CALL_FUNCTION_EX always take a kwargs argument)
 
     Python 3.15 will start with 3650
 
@@ -279,7 +280,7 @@ PC/launcher.c must also be updated.
 
 */
 
-#define PYC_MAGIC_NUMBER 3614
+#define PYC_MAGIC_NUMBER 3615
 /* This is equivalent to converting PYC_MAGIC_NUMBER to 2 bytes
    (little-endian) and then appending b'\r\n'. */
 #define PYC_MAGIC_NUMBER_TOKEN \