Expose `attributor-disable` to the new and old pass managers

The new and old pass managers (PassManagerBuilder.cpp and
PassBuilder.cpp) are exposed to an `extern` declaration of
`attributor-disable` option which will guard the addition of the
attributor passes to the pass pipelines.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D76871
diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index 483cb71..ec9252c3 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -160,11 +160,6 @@
     cl::desc("Verify that max-iterations is a tight bound for a fixpoint"),
     cl::init(false));
 
-static cl::opt<bool> DisableAttributor(
-    "attributor-disable", cl::Hidden,
-    cl::desc("Disable the attributor inter-procedural deduction pass."),
-    cl::init(true));
-
 static cl::opt<bool> AnnotateDeclarationCallSites(
     "attributor-annotate-decl-cs", cl::Hidden,
     cl::desc("Annotate call sites of function declarations."), cl::init(false));
@@ -8849,7 +8844,7 @@
                                      SetVector<Function *> &Functions,
                                      AnalysisGetter &AG,
                                      CallGraphUpdater &CGUpdater) {
-  if (DisableAttributor || Functions.empty())
+  if (Functions.empty())
     return false;
 
   LLVM_DEBUG(dbgs() << "[Attributor] Run on module with " << Functions.size()