Fix false positives from mjData stack leakage detection.

When built and run under address sanitizer (asan), `mj_markStack` and `mj_freeStack` are instrumented to detect leakage of mjData stack frames. When the compiler inlines several callees that call into mark/free in the same function, this instrumentation requires that the compiler retains separate mark/free calls for each original callee.

This change adds necessary optimization barriers to ensure that this is the case.

PiperOrigin-RevId: 609373993
Change-Id: I30dfd998fb66530735348e9715d92ee713f28210

src/engine/engine_io.h

@@ -110,12 +110,21 @@ MJAPI void mj_resetDataKeyframe(const mjModel* m, mjData* d, int key);
 // mjData arena allocate
 MJAPI void* mj_arenaAllocByte(mjData* d, size_t bytes, size_t alignment);
 
+#ifndef ADDRESS_SANITIZER
+
 // mjData mark stack frame
 MJAPI void mj_markStack(mjData* d);
 
 // mjData free stack frame
 MJAPI void mj_freeStack(mjData* d);
 
+#else
+
+void mj__markStack(mjData* d) __attribute__((noinline));
+void mj__freeStack(mjData* d) __attribute__((noinline));
+
+#endif  // ADDRESS_SANITIZER
+
 // mjData stack allocate
 MJAPI void* mj_stackAllocByte(mjData* d, size_t bytes, size_t alignment);