Reapply "Merge branch 'PHP-8.3' into PHP-8.4"

This reverts commit 83ca37483c, and
fixes the previous bad merge.

NEWS

@@ -1,5 +1,11 @@
 PHP                                                                        NEWS
 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
+?? ??? ????, PHP 8.4.2
+
+- Opcache:
+  . Fixed bug GH-16851 (JIT_G(enabled) not set correctly on other threads).
+    (dktapps)
+
 21 Nov 2024, PHP 8.4.1
 
 - BcMath:

ext/opcache/ZendAccelerator.c

@@ -3282,6 +3282,7 @@ static zend_result accel_post_startup(void)
 				zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not enable JIT: could not use reserved buffer!");
 			} else {
 				zend_jit_startup(ZSMMG(reserved), jit_size, reattached);
+				zend_jit_startup_ok = true;
 			}
 		}
 #endif

ext/opcache/jit/zend_jit.c

@@ -69,6 +69,8 @@ zend_jit_globals jit_globals;
 #define JIT_STUB_PREFIX "JIT$$"
 #define TRACE_PREFIX    "TRACE-"
 
+bool zend_jit_startup_ok = false;
+
 zend_ulong zend_jit_profile_counter = 0;
 int zend_jit_profile_counter_rid = -1;
 
@@ -3634,6 +3636,13 @@ static void zend_jit_reset_counters(void)
 
 void zend_jit_activate(void)
 {
+#ifdef ZTS
+	if (!zend_jit_startup_ok) {
+		JIT_G(enabled) = 0;
+		JIT_G(on) = 0;
+		return;
+	}
+#endif
 	zend_jit_profile_counter = 0;
 	if (JIT_G(on)) {
 		if (JIT_G(trigger) == ZEND_JIT_ON_HOT_COUNTERS) {

ext/opcache/jit/zend_jit.h

@@ -100,6 +100,8 @@ typedef struct _zend_jit_trace_rec zend_jit_trace_rec;
 typedef struct _zend_jit_trace_stack_frame zend_jit_trace_stack_frame;
 typedef struct _sym_node zend_sym_node;
 
+extern bool zend_jit_startup_ok;
+
 typedef struct _zend_jit_globals {
 	bool enabled;
 	bool on;