The steady drumbeat of warnings over the surge in risky corporate borrowing is growing louder and louder. Time and again, regulators in the U.S. and Europe have pointed to the hazards of businesses taking on too much debt. . . Some say regulators aren’t doing nearly enough to fix their blind spots. “I am not confident that regulators have or share among themselves the high-quality information that they need,” Erik F. Gerding, who specializes in financial regulation at University of Colorado Law School, said at a congressional hearing on leveraged loans on June 4. “We cannot wait until it is time to man the lifeboats to fully fund the iceberg patrol.”