Now that C++17 is official (https://www.iso.org/standard/68564.html), start changing the C++1z terminology over to C++17. NFC intended, these are all mechanical changes.

llvm-svn: 319688
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index 3a3eb5e..45b73f0 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -2480,7 +2480,7 @@
     // C++1z removes this restriction.
     QualType BeginType = BeginVar->getType(), EndType = EndVar->getType();
     if (!Context.hasSameType(BeginType, EndType)) {
-      Diag(RangeLoc, getLangOpts().CPlusPlus1z
+      Diag(RangeLoc, getLangOpts().CPlusPlus17
                          ? diag::warn_for_range_begin_end_types_differ
                          : diag::ext_for_range_begin_end_types_differ)
           << BeginType << EndType;