Clang plugin build fixes after upstream https://reviews.llvm.org/D84362

Bug: 1140409
Change-Id: I4b0c55fa46c877d4f08c5ffca33af899ef20d2a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2485222
Commit-Queue: Hans Wennborg <hans@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818882}

tools/clang/plugins/SuppressibleDiagnosticBuilder.h

@@ -26,9 +26,13 @@ class SuppressibleDiagnosticBuilder : public clang::DiagnosticBuilder {
 
   ~SuppressibleDiagnosticBuilder() {
     if (suppressed_) {
-      // Clear the counts and underlying data, so the base class destructor
+      // Clear the underlying data, so the base class destructor
       // doesn't try to emit the diagnostic.
+
+      // TODO(crbug.com/1140409) Remove in the next Clang roll.
+#ifndef LLVM_FORCE_HEAD_REVISION
       FlushCounts();
+#endif
       Clear();
       // Also clear the current diagnostic being processed by the
       // DiagnosticsEngine, since it won't be emitted.
@@ -36,6 +40,8 @@ class SuppressibleDiagnosticBuilder : public clang::DiagnosticBuilder {
     }
   }
 
+  // TODO(crbug.com/1140409) Remove in the next Clang roll.
+#ifndef LLVM_FORCE_HEAD_REVISION
   template <typename T>
   friend const SuppressibleDiagnosticBuilder& operator<<(
       const SuppressibleDiagnosticBuilder& builder,
@@ -44,6 +50,7 @@ class SuppressibleDiagnosticBuilder : public clang::DiagnosticBuilder {
     base_builder << value;
     return builder;
   }
+#endif
 
  private:
   clang::DiagnosticsEngine* const diagnostics_;