SAN FRANCISCO - Google's stock roared out of a long slumber Friday to produce the biggest shareholder windfall in U.S. history as investors rewarded the Internet company for promising to curb its spending on risky projects.A 16 percent surge in Google's publicly traded stock translated into an additional $65.1 billion in shareholder wealth, on paper at least.That barely topped the previous record one-day gain of $65 billion by Cisco Systems Inc.