Use - as separator for consistency with Crossgen2

Author: tmat

src/Compilers/Core/Portable/NativePdbWriter/PdbWriter.cs

@@ -775,7 +775,7 @@ public void WriteCompilerVersion(string language)
             var compilerAssembly = typeof(Compilation).Assembly;
             var fileVersion = Version.Parse(compilerAssembly.GetCustomAttribute<AssemblyFileVersionAttribute>().Version);
             var versionString = compilerAssembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>().InformationalVersion;
-            _symWriter.AddCompilerInfo((ushort)fileVersion.Major, (ushort)fileVersion.Minor, (ushort)fileVersion.Build, (ushort)fileVersion.Revision, $"{language}: {versionString}");
+            _symWriter.AddCompilerInfo((ushort)fileVersion.Major, (ushort)fileVersion.Minor, (ushort)fileVersion.Build, (ushort)fileVersion.Revision, $"{language} - {versionString}");
         }
     }
 }