Move registers struct to common.h

So that it can still be used in x64 builds

src/addresses.h

@@ -647,59 +647,6 @@ static int RCT2_CALLPROC_EBPSAFE(int address)
  */
 int RCT2_CALLFUNC_X(int address, int *_eax, int *_ebx, int *_ecx, int *_edx, int *_esi, int *_edi, int *_ebp);
 
-#pragma pack(push, 1)
-
-typedef struct registers {
-	union {
-		int eax;
-		short ax;
-		struct {
-			char al;
-			char ah;
-		};
-	};
-	union {
-		int ebx;
-		short bx;
-		struct {
-			char bl;
-			char bh;
-		};
-	};
-	union {
-		int ecx;
-		short cx;
-		struct {
-			char cl;
-			char ch;
-		};
-	};
-	union {
-		int edx;
-		short dx;
-		struct {
-			char dl;
-			char dh;
-		};
-	};
-	union {
-		int esi;
-		short si;
-	};
-	union {
-		int edi;
-		short di;
-	};
-	union {
-		int ebp;
-		short bp;
-	};
-} registers;
-
-assert_struct_size(registers, 7 * 4);
-
-#pragma pack(pop)
-
 static int RCT2_CALLFUNC_Y(int address, registers *inOut)
 {
 	return RCT2_CALLFUNC_X(address, &inOut->eax, &inOut->ebx, &inOut->ecx, &inOut->edx, &inOut->esi, &inOut->edi, &inOut->ebp);

src/common.h

@@ -89,4 +89,57 @@
 	#define FASTCALL
 #endif // PLATFORM_X86
 
+/**
+ * x86 register structure, only used for easy interop to RCT2 code.
+ */
+#pragma pack(push, 1)
+typedef struct registers {
+	union {
+		int eax;
+		short ax;
+		struct {
+			char al;
+			char ah;
+		};
+	};
+	union {
+		int ebx;
+		short bx;
+		struct {
+			char bl;
+			char bh;
+		};
+	};
+	union {
+		int ecx;
+		short cx;
+		struct {
+			char cl;
+			char ch;
+		};
+	};
+	union {
+		int edx;
+		short dx;
+		struct {
+			char dl;
+			char dh;
+		};
+	};
+	union {
+		int esi;
+		short si;
+	};
+	union {
+		int edi;
+		short di;
+	};
+	union {
+		int ebp;
+		short bp;
+	};
+} registers;
+assert_struct_size(registers, 7 * 4);
+#pragma pack(pop)
+
 #endif