revlog: refactor out _finddeltainfo from _addrevision
Splicing the code into smaller chunks should help understanding it,
and eventually override some parts in experimental branches to try
optimization.
BasedOnStyle: LLVM
IndentWidth: 8
UseTab: ForIndentation
BreakBeforeBraces: Linux
AllowShortIfStatementsOnASingleLine: false
IndentCaseLabels: false
AllowShortBlocksOnASingleLine: false
AllowShortFunctionsOnASingleLine: false