isCompilerGenerated

True when the C++ analyzer classified this instruction as compiler-introduced during clang's lowering of C++ → LLVM IR (alloca for return slots / mem2reg, phi, freeze, unreachable, llvm.dbg.* / llvm.lifetime.* intrinsics). Empty sourceFile with isCompilerGenerated = false is a debug-info-stripping regression signal — consumers can count it via the P6 summary line.