Include size in PAX extended header

bsdtar does not properly handle the base-256 encoded xstar size value.

Fixes #131

Author: isaacs

lib/write-entry.js

@@ -127,7 +127,7 @@ const WriteEntry = warner(class WriteEntry extends MiniPass {
         mtime: this.header.mtime,
         path: this.path,
         linkpath: this.linkpath,
-        size: this.size,
+        size: this.header.size,
         uid: this.portable ? null : this.header.uid,
         uname: this.portable ? null : this.header.uname,
         dev: this.portable ? null : this.stat.dev,

test/write-entry.js

@@ -690,7 +690,7 @@ t.test('portable entries, nothing platform-specific', t => {
     gname: null,
     linkpath: null,
     path: 'long-path/r/e/a/l/l/y/-/d/e/e/p/-/f/o/l/d/e/r/-/p/a/t/h/Ω.txt',
-    size: null,
+    size: 2,
     uid: null,
     uname: null,
     dev: null,