Rename method

src/Compilers/Core/Portable/CommandLine/CommonCompiler.cs

@@ -572,7 +572,7 @@ internal static bool HasUnsuppressedErrors(DiagnosticBag diagnostics)
         {
             foreach (var diag in diagnostics.AsEnumerable())
             {
-                if (diag.IsUnsuppressedError())
+                if (diag.IsUnsuppressableError())
                 {
                     return true;
                 }

src/Compilers/Core/Portable/Compilation/Compilation.cs

@@ -1378,7 +1378,7 @@ internal bool FilterAndAppendDiagnostics(DiagnosticBag accumulator, IEnumerable<
                 {
                     continue;
                 }
-                else if (filtered.IsUnsuppressedError())
+                else if (filtered.IsUnsuppressableError())
                 {
                     hasError = true;
                 }

src/Compilers/Core/Portable/Diagnostic/Diagnostic.cs

@@ -565,7 +565,7 @@ internal virtual bool IsNotConfigurable()
         /// Only diagnostics which have default severity error and are tagged as NotConfigurable fall in this bucket.
         /// This includes all compiler error diagnostics and specific analyzer error diagnostics that are marked as not configurable by the analyzer author.
         /// </summary>
-        internal bool IsUnsuppressedError()
+        internal bool IsUnsuppressableError()
             => DefaultSeverity == DiagnosticSeverity.Error && IsNotConfigurable();
     }