Make x86_64-unknown-linux-gnu.json true to its name

Author: edef1c

src/test/run-make/target-specs/x86_64-unknown-linux-gnu.json

@@ -1,9 +1,10 @@
 {
-    "data-layout": "e-p:32:32-f64:32:64-i64:32:64-f80:32:32-n8:16:32",
-    "llvm-target": "i686-unknown-linux-gnu",
+    "pre-link-args": ["-m64"],
+    "data-layout": "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128",
+    "llvm-target": "x86_64-unknown-linux-gnu",
     "target-endian": "little",
-    "target-word-size": "32",
-    "arch": "x86",
+    "target-word-size": "64",
+    "arch": "x86_64",
     "os": "linux",
     "morestack": false
 }