savestate: rzip size must be 64-bit on all platforms

core/archive/rzip.cpp

@@ -39,6 +39,12 @@ bool RZipFile::Open(const std::string& path, bool write)
 			Close();
 			return false;
 		}
+		// savestates created on 32-bit platforms used to have a 32-bit size
+		if (size >> 32 != 0)
+		{
+			size &= 0xffffffff;
+			std::fseek(file, -4, SEEK_CUR);
+		}
 		chunk = new u8[maxChunkSize];
 		chunkIndex = 0;
 		chunkSize = 0;
@@ -109,9 +115,10 @@ size_t RZipFile::Write(const void *data, size_t length)
 	verify(std::ftell(file) == 0);
 
 	maxChunkSize = 1024 * 1024;
+	size = length;
 	if (std::fwrite(RZipHeader, sizeof(RZipHeader), 1, file) != 1
 		|| std::fwrite(&maxChunkSize, sizeof(maxChunkSize), 1, file) != 1
-		|| std::fwrite(&length, sizeof(length), 1, file) != 1)
+		|| std::fwrite(&size, sizeof(size), 1, file) != 1)
 		return 0;
 	const u8 *p = (const u8 *)data;
 	// compression output buffer must be 0.1% larger + 12 bytes

core/archive/rzip.h

@@ -35,7 +35,7 @@ public:
 
 private:
 	FILE *file = nullptr;
-	size_t size = 0;
+	u64 size = 0;
 	u32 maxChunkSize = 0;
 	u8 *chunk = nullptr;
 	u32 chunkSize = 0;