testlib: add `--raw-sha1` option to `f`

This will be used in the patch fixing the ignore hash collision in
dirstate-v2 to check the behavior of the new hashing function.

tests/f

@@ -63,7 +63,16 b' def visit(opts, filenames, outfile):'
         if isfile:
             if opts.type:
                 facts.append(b'file')
-            if any((opts.hexdump, opts.dump, opts.md5, opts.sha1, opts.sha256)):
+            needs_reading = (
+                opts.hexdump,
+                opts.dump,
+                opts.md5,
+                opts.sha1,
+                opts.raw_sha1,
+                opts.sha256,
+            )
+
+            if any(needs_reading):
                 with open(f, 'rb') as fobj:
                     content = fobj.read()
         elif islink:
@@ -101,6 +110,9 b' def visit(opts, filenames, outfile):'
         if opts.md5 and content is not None:
             h = hashlib.md5(content)
             facts.append(b'md5=%s' % binascii.hexlify(h.digest())[: opts.bytes])
+        if opts.raw_sha1 and content is not None:
+            h = hashlib.sha1(content)
+            facts.append(b'raw-sha1=%s' % h.digest()[: opts.bytes])
         if opts.sha1 and content is not None:
             h = hashlib.sha1(content)
             facts.append(
@@ -186,6 +198,12 b' if __name__ == "__main__":'
     )
     parser.add_option(
         "",
+        "--raw-sha1",
+        action="store_true",
+        help="show raw bytes of the sha1 hash of the content",
+    )
+    parser.add_option(
+        "",
         "--sha256",
         action="store_true",
         help="show sha256 hash of the content",

tests/test-tools.t

@@ -13,6 +13,7 b' Tests of the file helper tool'
                           check if file is newer (or same)
     -r, --recurse         recurse into directories
     -S, --sha1            show sha1 hash of the content
+    --raw-sha1            show raw bytes of the sha1 hash of the content
     --sha256              show sha256 hash of the content
     -M, --md5             show md5 hash of the content
     -D, --dump            dump file content