MachO/DebugSymbols: fix debug line offset

In c8b78706b74d16ed21113096d2b47717abb53d4d I incorrectly made it be the
line offset from Decl to function lbrace; it needed to be line offset
from lbrace to rbrace.
f4ee46e839Andrew Kelley committed on 5/16/2021, 9:20:51 PMparentc8b7870
1 file changedLine totals unavailable