[doc] Removed obsolete -count-aa from AliasAnalysis documentation

Summary:
This patch removes references to AliasAnalysisCounter pass from the AliasAnalysis documentation. That pass have been eliminated in 2015, at revision trunk@247167.

Reviewed By: hfinkel

Differential Revision: https://reviews.llvm.org/D45876

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330590 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed