Light up to emit eager imports on meta Python

Summary: Currently on 3.14 we don't ever emit `EAGER_IMPORT_NAME`. This changes us to check if the opcode is defined by the interpreter and emit it only in that case. That way we'll work on stock CPython or meta-Python.

Reviewed By: alexmalyshev

Differential Revision: D83846390

fbshipit-source-id: d83e474d4f838c1902f556e80961f6f519057470

Author: DinoV

cinderx/PythonLib/cinderx/compiler/opcodes.py

@@ -304,6 +304,7 @@
         DELETE_SUBSCR=2,
         DICT_MERGE=lambda oparg: 5 + (oparg - 1),
         DICT_UPDATE=lambda oparg: 2 + (oparg - 1),
+        EAGER_IMPORT_NAME=2,
         END_ASYNC_FOR=2,
         END_FOR=1,
         END_SEND=2,
@@ -545,6 +546,7 @@
         DELETE_SUBSCR=0,
         DICT_MERGE=lambda oparg: 4 + (oparg - 1),
         DICT_UPDATE=lambda oparg: 1 + (oparg - 1),
+        EAGER_IMPORT_NAME=1,
         END_ASYNC_FOR=0,
         END_FOR=0,
         END_SEND=1,

cinderx/PythonLib/cinderx/compiler/pycodegen.py

@@ -13,6 +13,7 @@
     import importlib.util
     import itertools
     import marshal
+    import opcode
     import os
     import sys
     from ast import AST, ClassDef
@@ -3897,7 +3898,11 @@ def check_name(self, name: str) -> int:
         return super().check_name(name)
 
     def emit_import_name(self, name: str) -> None:
-        if isinstance(self.scope, ModuleScope) and not self.setups:
+        # If we're not on meta-Python we don't EAGER_IMPORT_NAME so only
+        # emit it when it's available.
+        if "EAGER_IMPORT_NAME" not in opcode.opmap or (
+            isinstance(self.scope, ModuleScope) and not self.setups
+        ):
             self.emit("IMPORT_NAME", name)
         else:
             self.emit("EAGER_IMPORT_NAME", name)
@@ -6359,9 +6364,6 @@ def make_try_body_block(self) -> Block | None:
     def emit_binary_subscr(self) -> None:
         self.emit("BINARY_OP", find_op_idx("NB_SUBSCR"))
 
-    def emit_import_name(self, name: str) -> None:
-        self.emit("IMPORT_NAME", name)
-
     def emit_load_assertion_error(self, loc: AST | SrcLocation | None = None) -> None:
         if loc:
             self.graph.emit_with_loc("LOAD_COMMON_CONSTANT", AssertionError, loc)