[Testing] Add support for building binutils with mingw64

.gitignore

@@ -95,10 +95,10 @@ node_modules/.bin/
 /attic/
 /content/
 /third_party/binutils/binutils-2.24.tar.gz
+/third_party/binutils/binutils-2.24/
 /third_party/binutils/bin/
 /third_party/binutils/powerpc-none-elf/
 /third_party/binutils/share/
-/third_party/binutils/binutils*
 /third_party/vasm/
 /tools/shader-playground/*.dll
 /profile_print_times.py

third_party/binutils/binutils-2.24-mingw64.patch

@@ -0,0 +1,51 @@
+diff -u -P -r libiberty/strerror.c libiberty/strerror.c
+--- libiberty/strerror.c	2013-11-04 07:33:39.000000000 -0800
++++ libiberty/strerror.c	2026-02-14 00:00:00.000000000 -0800
+@@ -469,8 +469,12 @@
+
+ #else
+
++#ifndef sys_nerr
+ extern int sys_nerr;
++#endif
++#ifndef sys_errlist
+ extern char *sys_errlist[];
++#endif
+
+ #endif
+
+diff -u -P -r libiberty/waitpid.c libiberty/waitpid.c
+--- libiberty/waitpid.c	2013-11-04 07:33:39.000000000 -0800
++++ libiberty/waitpid.c	2026-02-14 00:00:00.000000000 -0800
+@@ -24,6 +24,13 @@
+ #include <sys/wait.h>
+ #endif
+
++#if defined(_WIN32) || defined(__MINGW32__)
++pid_t
++waitpid (pid_t pid, int *stat_loc, int options ATTRIBUTE_UNUSED)
++{
++  return -1;
++}
++#else
+ pid_t
+ waitpid (pid_t pid, int *stat_loc, int options ATTRIBUTE_UNUSED)
+ {
+@@ -33,3 +40,4 @@
+ 	return wpid;
+     }
+ }
++#endif
+diff -u -P -r intl/dcigettext.c intl/dcigettext.c
+--- intl/dcigettext.c	2013-11-04 07:33:39.000000000 -0800
++++ intl/dcigettext.c	2026-02-14 00:00:00.000000000 -0800
+@@ -148,7 +148,9 @@
+ char *getwd ();
+ #  define getcwd(buf, max) getwd (buf)
+ # else
++#  if !defined HAVE_UNISTD_H
+ char *getcwd ();
++#  endif
+ # endif
+ # ifndef HAVE_STPCPY
+ static char *stpcpy PARAMS ((char *dest, const char *src));

third_party/binutils/build.sh

@@ -37,6 +37,12 @@ echo ""
 echo "Patching binutils with vmx128 support..."
 patch -p0 < $THIS_SCRIPT_DIR/binutils-$SNAPSHOT_VERSION-vmx128.patch
 
+if [ "$(uname -o 2>/dev/null)" = "Msys" ] && [ -n "$MINGW_PREFIX" ]; then
+  echo ""
+  echo "Patching binutils for mingw64 compatibility..."
+  patch -p0 < $THIS_SCRIPT_DIR/binutils-$SNAPSHOT_VERSION-mingw64.patch
+fi
+
 echo ""
 echo "Running ./configure..."
 ./configure \
@@ -58,6 +64,16 @@ echo ""
 echo "Running make install..."
 make install
 
+if [ "$(uname -o 2>/dev/null)" = "Msys" ] && [ -n "$MINGW_PREFIX" ]; then
+  echo ""
+  echo "Copying MinGW runtime DLLs..."
+  for dll in libiconv-2.dll zlib1.dll; do
+    if [ -f "$MINGW_PREFIX/bin/$dll" ] && [ ! -f "$THIS_SCRIPT_DIR/bin/$dll" ]; then
+      cp "$MINGW_PREFIX/bin/$dll" "$THIS_SCRIPT_DIR/bin/"
+    fi
+  done
+fi
+
 cd ..
 
 echo ""