Add definitions for CHeliSAInterface (#3686)

* Update CHeliSA.h

* Update CHeliSA.h

Client/game_sa/CHeliSA.h

@@ -15,10 +15,47 @@
 
 class CHeliSAInterface : public CAutomobileSAInterface
 {
+public:
+    std::uint8_t m_heliFlags;
+
+    std::uint8_t _pad1[3];
+    std::uint32_t m_leftRightSkid;
+    std::uint32_t m_steeringUpDown;
+    std::uint32_t m_steeringLeftRight;
+    std::uint32_t m_accelerationBreakStatus;
+    std::uint32_t field_99C;
+    std::uint32_t m_rotorZ;
+    std::uint32_t m_secondRotorZ;
+    std::uint32_t m_maxAltitude;
+    std::uint32_t field_9AC;
+    std::uint32_t m_minAltitude;
+    std::uint32_t field_9B4;
+    std::uint8_t field_9B8;
+    std::uint8_t m_numSwatOccupants;
+    std::uint8_t m_swatIDs[4];
+
+    std::uint8_t _pad2[2];
+    std::uint32_t field_9C0[4];
+    std::uint32_t field_9D0;
+
+    std::uint32_t m_particlesList;
+    std::uint8_t field_9D8[24];
+    std::uint32_t field_9F0;
+    CVector m_searchLightTarget;
+    std::uint32_t m_searchLightIntensity;
+    std::uint32_t field_A04;
+    std::uint32_t field_A08;
+    std::uint32_t m_gunflashFx;
+    std::uint8_t m_firingMultiplier;
+    std::uint8_t m_searchLightEnabled;
+    std::uint8_t _pad3[2];
+    std::uint32_t field_A14;
 };
+static_assert(sizeof(CHeliSAInterface) == 0xA18, "Invalid size for CHeliSAInterface");
 
 class CHeliSA final : public virtual CHeli, public virtual CAutomobileSA
 {
 public:
     CHeliSA(CHeliSAInterface* pInterface);
+    CHeliSAInterface* GetHeliInterface() noexcept { return reinterpret_cast<CHeliSAInterface*>(GetInterface()); }
 };