This patch cleans up the ProfileInfo by

*) introducing new data type and export function of edge info for whole function (preparation for next patch).
*) renaming variables to make clear distinction between data and containers that contain this data.
*) updated comments and whitespaces.
*) made ProfileInfo::MissingValue a double (as it should be...).

(Discussed at http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090817/084955.html.)

llvm-svn: 79940