Remove compiler name autodetection

Also add compilerName: csc to every project.json to compensate.

src/Microsoft.DotNet.Cli.Utils/project.json

@@ -1,5 +1,6 @@
 {
     "version": "1.0.0-*",
+    "compilerName": "csc",
 
     "shared": "**/*.cs",
 

src/Microsoft.DotNet.Cli/project.json

@@ -1,6 +1,7 @@
 {
   "name": "dotnet",
   "version": "1.0.0-*",
+  "compilerName": "csc",
   "compilationOptions": {
     "emitEntryPoint": true
   },

src/Microsoft.DotNet.Tools.Compiler.Csc/project.json

@@ -1,6 +1,7 @@
 {
   "name": "dotnet-compile-csc",
   "version": "1.0.0-*",
+  "compilerName": "csc",
   "compilationOptions": {
     "emitEntryPoint": true
   },

src/Microsoft.DotNet.Tools.Compiler/Program.cs

@@ -191,9 +191,9 @@ namespace Microsoft.DotNet.Tools.Compiler
             }
 
             var compilerName = context.ProjectFile.CompilerName;
-            if (compilerName == null && !TryDetectCompilerName(sourceFiles, out compilerName))
+            if (compilerName == null)
             {
-                Console.Error.WriteLine("Could not detect the compiler name. Please specify it in the project.json file.");
+                Console.Error.WriteLine("Could not find the compiler name. Please specify it in the project.json file.");
                 return false;
             }
 
@@ -242,55 +242,6 @@ namespace Microsoft.DotNet.Tools.Compiler
             return success;
         }
 
-        private static readonly KeyValuePair<string, string>[] s_compilerNameLookupTable =
-        {
-            new KeyValuePair<string, string>(".cs", "csc"),
-            new KeyValuePair<string, string>(".vb", "vbc"),
-            new KeyValuePair<string, string>(".fs", "fsc")
-        };
-
-        /// <summary>
-        /// Uses the extension on the source files to try to detect the
-        /// compiler. If the source files have different extensions or the
-        /// extension is not recognized, returns false.
-        /// </summary>
-        private static bool TryDetectCompilerName(IEnumerable<string> sourceFiles, out string compilerName)
-        {
-            compilerName = null;
-            string extension = null;
-            foreach (var file in sourceFiles)
-            {
-                if (!Path.HasExtension(file))
-                {
-                    return false;
-                }
-
-                var tmpExtension = Path.GetExtension(file);
-                extension = extension ?? tmpExtension;
-
-                if (extension != tmpExtension)
-                {
-                    return false;
-                }
-            }
-
-            if (extension == null)
-            {
-                return false;
-            }
-
-            foreach (var kvp in s_compilerNameLookupTable)
-            {
-                if (extension == kvp.Key)
-                {
-                    compilerName = kvp.Value;
-                    return true;
-                }
-            }
-
-            return false;
-        }
-
         private static void PrintSummary(List<DiagnosticMessage> diagnostics)
         {
             Reporter.Output.Writer.WriteLine();

src/Microsoft.DotNet.Tools.Compiler/project.json

@@ -1,6 +1,7 @@
 {
   "name": "dotnet-compile",
   "version": "1.0.0-*",
+  "compilerName": "csc",
   "compilationOptions": {
     "emitEntryPoint": true
   },

src/Microsoft.DotNet.Tools.Publish/project.json

@@ -1,6 +1,7 @@
 {
   "name": "dotnet-publish",
   "version": "1.0.0-*",
+  "compilerName": "csc",
   "compilationOptions": {
     "emitEntryPoint": true
   },

src/Microsoft.DotNet.Tools.Resgen/project.json

@@ -1,6 +1,7 @@
 {
   "name": "resgen",
   "version": "1.0.0-*",
+  "compilerName": "csc",
   "compilationOptions": {
     "emitEntryPoint": true
   },

src/Microsoft.Extensions.ProjectModel/project.json

@@ -1,7 +1,7 @@
 {
   "version": "1.0.0-*",
   "description": "Types to model a .NET Project",
-
+  "compilerName": "csc",
   "dependencies": {
     "Microsoft.CSharp": "4.0.1-beta-23419",
     "System.Collections": "4.0.11-beta-23419",