gh-134584: Decref elimination for float ops in the JIT (GH-134588)

This PR adds a PyJitRef API to the JIT's optimizer that mimics the _PyStackRef API. This allows it to track references and their stack lifetimes properly. Thus opening up the doorway to refcount elimination in the JIT.

Python/optimizer_analysis.c

@@ -347,8 +347,8 @@ static int
 optimize_to_bool(
     _PyUOpInstruction *this_instr,
     JitOptContext *ctx,
-    JitOptSymbol *value,
-    JitOptSymbol **result_ptr)
+    JitOptRef value,
+    JitOptRef *result_ptr)
 {
     if (sym_matches_type(value, &PyBool_Type)) {
         REPLACE_OP(this_instr, _NOP, 0, 0);
@@ -375,7 +375,7 @@ eliminate_pop_guard(_PyUOpInstruction *this_instr, bool exit)
     }
 }
 
-static JitOptSymbol *
+static JitOptRef
 lookup_attr(JitOptContext *ctx, _PyUOpInstruction *this_instr,
             PyTypeObject *type, PyObject *name, uint16_t immortal,
             uint16_t mortal)
@@ -440,6 +440,13 @@ get_code_with_logging(_PyUOpInstruction *op)
     return co;
 }
 
+// TODO (gh-134584) generate most of this table automatically
+const uint16_t op_without_decref_inputs[MAX_UOP_ID + 1] = {
+    [_BINARY_OP_MULTIPLY_FLOAT] = _BINARY_OP_MULTIPLY_FLOAT__NO_DECREF_INPUTS,
+    [_BINARY_OP_ADD_FLOAT] = _BINARY_OP_ADD_FLOAT__NO_DECREF_INPUTS,
+    [_BINARY_OP_SUBTRACT_FLOAT] = _BINARY_OP_SUBTRACT_FLOAT__NO_DECREF_INPUTS,
+};
+
 /* 1 for success, 0 for not ready, cannot error at the moment. */
 static int
 optimize_uops(
@@ -477,7 +484,7 @@ optimize_uops(
 
         int oparg = this_instr->oparg;
         opcode = this_instr->opcode;
-        JitOptSymbol **stack_pointer = ctx->frame->stack_pointer;
+        JitOptRef *stack_pointer = ctx->frame->stack_pointer;
 
 #ifdef Py_DEBUG
         if (get_lltrace() >= 3) {