MoonchildProductions#1251 - Part 23: Allow AMD64 build to work.

https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/Build_Instructions/Compiling_32-bit_Firefox_on_a_Linux_64-bit_OS

Setting this up turned out to be easier than I thought it would be. All I had to do was apply these instructions in reverse and add the following to my .mozconfig file:

CC="gcc -m64"
CXX="g++ -m64"
AS="gas --64"
ac_add_options --target=x86_64-pc-solaris2.11
export PKG_CONFIG_PATH=/usr/lib/amd64/pkgconfig
ac_add_options --libdir=/usr/lib/amd64
ac_add_options --x-libraries=/usr/lib/amd64

Most of these changes were fairly trivial, just requiring me to make a few of the changes I made earlier conditional on a 32-bit build. The biggest challenge was figuring out why the JavaScript engine triggered a segfault everytime it tried to allocate memory. But this patch fixes it:

https://github.com/OpenIndiana/oi-userland/blob/oi/hipster/components/web/firefox/patches/patch-js_src_gc_Memory.cpp.patch

Turns out that Solaris on AMD64 handles memory management in a fairly unusual way with a segmented memory model, but it's not that different from what we see on other 64-bit processors. In fact, I saw a SPARC crash for a similar reason, and noticed that it looked just like mine except the numbers in the first segment were reversed. Having played around with hex editors before, I had a feeling I might be dealing with a little-endian version of a big-endian problem, but I didn't expect that knowledge to actually yield an easy solution.

https://bugzilla.mozilla.org/show_bug.cgi?id=577056

https://www.oracle.com/technetwork/server-storage/solaris10/solaris-memory-135224.html

As far as I can tell, this was the last barrier to an AMD64 Solaris build of Pale Moon.

xpcom/string/nsTSubstring.h

@@ -9,7 +9,12 @@
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/IntegerTypeTraits.h"
 #include "mozilla/Span.h"
-#ifdef XP_SOLARIS
+
+// Solaris defines pid_t to be long on ILP32 and int on LP64. I checked in 
+// sys/types.h. AMD64 and SPARC64 builds don't need this fix at all, 
+// while all 32-bit builds do.
+
+#if defined(XP_SOLARIS) && !defined(__LP64__)
 #include <unistd.h>
 #endif
 
@@ -590,7 +595,7 @@ public:
     const char* fmt = aRadix == 10 ? "%d" : aRadix == 8 ? "%o" : "%x";
     AppendPrintf(fmt, aInteger);
   }
-#ifdef XP_SOLARIS
+#if defined(XP_SOLARIS) && !defined(__LP64__)
   void AppendInt(pid_t aInteger)
   { 
    AppendPrintf("%lu", aInteger);