Patches for 64bit linux

[gaeorn]

This patch fixes assembler errors on some 64bit systems.

Index: common/crc32.cpp
===================================================================
--- common/crc32.cpp    (revision 1)
+++ common/crc32.cpp    (working copy)
@@ -112,6 +112,14 @@
 #undef i386    //darwin seems to think we are generating PIC, and we clobber ebx
 #endif

+/* Some 64bit systems do not like the i386 assembly code below. However, some 64bit
+   systems do work with the assembly code below. We #undef i386 to be on the safe
+   side if we are compiling 64bit. */
+
+#ifdef __x86_64__
+#undef i386
+#endif
+
 uint32 CRC32::Update(const int8* buf, uint32 bufsize, uint32 crc32) {
 #if defined(WIN32)
        // Register use: