isSource

Analyzer-reported roles/classification, preserved for diagram filtering: taint isSource / isSink, a isBranch terminator, and isCompilerGenerated — IR introduced by clang's lowering (alloca / phi / llvm.dbg.*) vs a real source-level "code instruction". The diagram-level transforms key off these (summarized = sources/sinks; source-code level = !isCompilerGenerated).