GH-128682: Account for escapes in DECREF_INPUTS (GH-129953)

* Handle escapes in DECREF_INPUTS

* Mark a few more functions as escaping

* Replace DECREF_INPUTS with PyStackRef_CLOSE where possible

Tools/cases_generator/cwriter.py

@@ -15,6 +15,8 @@ class CWriter:
         self.line_directives = line_directives
         self.last_token = None
         self.newline = True
+        self.pending_spill = False
+        self.pending_reload = False
 
     def set_position(self, tkn: Token) -> None:
         if self.last_token is not None:
@@ -33,6 +35,7 @@ class CWriter:
         self.newline = False
 
     def emit_at(self, txt: str, where: Token) -> None:
+        self.maybe_write_spill()
         self.set_position(where)
         self.out.write(txt)
 
@@ -109,6 +112,7 @@ class CWriter:
         self.last_token = None
 
     def emit(self, txt: str | Token) -> None:
+        self.maybe_write_spill()
         if isinstance(txt, Token):
             self.emit_token(txt)
         elif isinstance(txt, str):
@@ -122,6 +126,28 @@ class CWriter:
         self.newline = True
         self.last_token = None
 
+    def emit_spill(self) -> None:
+        if self.pending_reload:
+            self.pending_reload = False
+            return
+        assert not self.pending_spill
+        self.pending_spill = True
+
+    def maybe_write_spill(self) -> None:
+        if self.pending_spill:
+            self.pending_spill = False
+            self.emit_str("_PyFrame_SetStackPointer(frame, stack_pointer);\n")
+        elif self.pending_reload:
+            self.pending_reload = False
+            self.emit_str("stack_pointer = _PyFrame_GetStackPointer(frame);\n")
+
+    def emit_reload(self) -> None:
+        if self.pending_spill:
+            self.pending_spill = False
+            return
+        assert not self.pending_reload
+        self.pending_reload = True
+
     @contextlib.contextmanager
     def header_guard(self, name: str) -> Iterator[None]:
         self.out.write(