[Diag] Add getter shouldAlwaysPrint. NFC

For the new hotness attribute, the API will take the pass rather than
the pass name so we can no longer play the trick of AlwaysPrint being a
special pass name. This adds a getter to help the transition.

There is also a corresponding clang patch.

llvm-svn: 274100
diff --git a/llvm/lib/Transforms/Scalar/LoopDistribute.cpp b/llvm/lib/Transforms/Scalar/LoopDistribute.cpp
index 464db8e..a07121e 100644
--- a/llvm/lib/Transforms/Scalar/LoopDistribute.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopDistribute.cpp
@@ -765,8 +765,9 @@
     // With Rpass-analysis report why.  This is on by default if distribution
     // was requested explicitly.
     emitOptimizationRemarkAnalysis(
-        Ctx, Forced ? DiagnosticInfo::AlwaysPrint : LDIST_NAME, *F,
-        L->getStartLoc(), Twine("loop not distributed: ") + Message);
+        Ctx, Forced ? DiagnosticInfoOptimizationRemarkAnalysis::AlwaysPrint
+                    : LDIST_NAME,
+        *F, L->getStartLoc(), Twine("loop not distributed: ") + Message);
 
     // Also issue a warning if distribution was requested explicitly but it
     // failed.