deps: cherry-pick cc55747 from V8 upstream

This fixes the flaky message/console test on our CI.

Original commit message:
  [test/message] Allow numbers to have more than one leading digit.

  The {NUMBER} regexp only allowed one, leading to occasional test
  failures such as:
  https://build.chromium.org/p/client.v8/builders/V8%20Mac%20-%20debug/builds/17156

  Bug:
  Change-Id: I25a08b80640d9af19ba70c61c846163685f1cb82
  Reviewed-on: https://chromium-review.googlesource.com/753322
  Reviewed-by: Franziska Hinkelmann <[email protected]>
  Commit-Queue: Georg Neis <[email protected]>
  Cr-Commit-Position: refs/heads/master@{#49109}

PR-URL: #16890
Ref: nodejs/build#936
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Michaël Zasso <[email protected]>
Reviewed-By: Daniel Bevenius <[email protected]>
Reviewed-By: James M Snell <[email protected]>

deps/v8/include/v8-version.h

@@ -11,7 +11,7 @@
 #define V8_MAJOR_VERSION 6
 #define V8_MINOR_VERSION 1
 #define V8_BUILD_NUMBER 534
-#define V8_PATCH_LEVEL 47
+#define V8_PATCH_LEVEL 48
 
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)

deps/v8/test/message/testcfg.py

@@ -107,7 +107,7 @@ def IsFailureOutput(self, testcase):
         expected_lines, actual_lines, fillvalue=''):
       pattern = re.escape(expected.rstrip() % env)
       pattern = pattern.replace("\\*", ".*")
-      pattern = pattern.replace("\\{NUMBER\\}", "\d(?:\.\d*)?")
+      pattern = pattern.replace("\\{NUMBER\\}", "\d+(?:\.\d*)?")
       pattern = "^%s$" % pattern
       if not re.match(pattern, actual):
         return True