deps: cherry-pick 081fce3 from V8 upstream

Original commit message:
  ThreadTicks::Now support for Solaris
  BUG=v8:5739

  Review-Url: https://codereview.chromium.org/2576903004
  Cr-Commit-Position: refs/heads/master@{#41771}

PR-URL: #10342
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>

Author: Matt Loring

deps/v8/include/v8-version.h

@@ -11,7 +11,7 @@
 #define V8_MAJOR_VERSION 5
 #define V8_MINOR_VERSION 4
 #define V8_BUILD_NUMBER 500
-#define V8_PATCH_LEVEL 44
+#define V8_PATCH_LEVEL 45
 
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)

deps/v8/src/base/platform/time.cc

@@ -639,7 +639,7 @@ bool TimeTicks::IsHighResolutionClockWorking() {
 
 bool ThreadTicks::IsSupported() {
 #if (defined(_POSIX_THREAD_CPUTIME) && (_POSIX_THREAD_CPUTIME >= 0)) || \
-  defined(V8_OS_MACOSX) || defined(V8_OS_ANDROID)
+    defined(V8_OS_MACOSX) || defined(V8_OS_ANDROID) || defined(V8_OS_SOLARIS)
   return true;
 #elif defined(V8_OS_WIN)
   return IsSupportedWin();
@@ -655,6 +655,8 @@ ThreadTicks ThreadTicks::Now() {
 #elif(defined(_POSIX_THREAD_CPUTIME) && (_POSIX_THREAD_CPUTIME >= 0)) || \
   defined(V8_OS_ANDROID)
   return ThreadTicks(ClockNow(CLOCK_THREAD_CPUTIME_ID));
+#elif V8_OS_SOLARIS
+  return ThreadTicks(gethrvtime() / Time::kNanosecondsPerMicrosecond);
 #elif V8_OS_WIN
   return ThreadTicks::GetForThread(::GetCurrentThread());
 #else