cmd/go: update PE header magic for files generated by GNU ld

Change-Id: I2d2ea233f976aab3f356f9b508cdd246d5013e32
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/7536Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/go/build.go

@@ -1261,15 +1261,15 @@ func (b *builder) cover(a *action, dst, src string, perm os.FileMode, varName st
 }
 
 var objectMagic = [][]byte{
-	{'!', '<', 'a', 'r', 'c', 'h', '>', '\n'},        // Package archive
-	{'\x7F', 'E', 'L', 'F'},                          // ELF
-	{0xFE, 0xED, 0xFA, 0xCE},                         // Mach-O big-endian 32-bit
-	{0xFE, 0xED, 0xFA, 0xCF},                         // Mach-O big-endian 64-bit
-	{0xCE, 0xFA, 0xED, 0xFE},                         // Mach-O little-endian 32-bit
-	{0xCF, 0xFA, 0xED, 0xFE},                         // Mach-O little-endian 64-bit
-	{0x4d, 0x5a, 0x90, 0x00, 0x03, 0x00, 0x04, 0x00}, // PE (Windows) as generated by 6l/8l
-	{0x00, 0x00, 0x01, 0xEB},                         // Plan 9 i386
-	{0x00, 0x00, 0x8a, 0x97},                         // Plan 9 amd64
+	{'!', '<', 'a', 'r', 'c', 'h', '>', '\n'}, // Package archive
+	{'\x7F', 'E', 'L', 'F'},                   // ELF
+	{0xFE, 0xED, 0xFA, 0xCE},                  // Mach-O big-endian 32-bit
+	{0xFE, 0xED, 0xFA, 0xCF},                  // Mach-O big-endian 64-bit
+	{0xCE, 0xFA, 0xED, 0xFE},                  // Mach-O little-endian 32-bit
+	{0xCF, 0xFA, 0xED, 0xFE},                  // Mach-O little-endian 64-bit
+	{0x4d, 0x5a, 0x90, 0x00, 0x03, 0x00},      // PE (Windows) as generated by 6l/8l and gcc
+	{0x00, 0x00, 0x01, 0xEB},                  // Plan 9 i386
+	{0x00, 0x00, 0x8a, 0x97},                  // Plan 9 amd64
 }
 
 func isObject(s string) bool {