This patch extends BasicStoreManager::getInitialStore() to include code that symbolicates input variables.
It also removes redundant handling of ImplicitParamDecl, since it is a subclass of VarDecl.

llvm-svn: 54993

Moved RemoveDeadBindings logic for the contents of 'Store' to a virtual RemoveDeadBindings method in StoreManager.

llvm-svn: 53726

current store implementation is now encapsulated by BasicStore.

These changes prompted some long due constification of ValueState. Much of the
diffs in this patch include adding "const" qualifiers.

llvm-svn: 53423