Wire up /runtimemetadataversion to the build task (#11404)

Fixes #5608

src/Compilers/Core/MSBuildTask/Shared/ManagedCompiler.cs

@@ -230,6 +230,12 @@ public ITaskItem[] Resources
             get { return (ITaskItem[])_store[nameof(Resources)]; }
         }
 
+        public string RuntimeMetadataVersion
+        {
+            set { _store[nameof(RuntimeMetadataVersion)] = value; }
+            get { return (string)_store[nameof(RuntimeMetadataVersion)]; }
+        }
+
         public ITaskItem[] ResponseFiles
         {
             set { _store[nameof(ResponseFiles)] = value; }
@@ -691,6 +697,7 @@ internal void AddResponseFileCommandsForSwitchesSinceInitialReleaseThatAreNeeded
         {
             commandLine.AppendPlusOrMinusSwitch("/deterministic", _store, nameof(Deterministic));
             commandLine.AppendPlusOrMinusSwitch("/publicsign", _store, nameof(PublicSign));
+            commandLine.AppendSwitchIfNotNull("/runtimemetadataversion:", RuntimeMetadataVersion);
 
             AddFeatures(commandLine, Features);
         }

src/Compilers/Core/MSBuildTaskTests/CscTests.cs

@@ -76,6 +76,20 @@ public void PublicSignFlag()
             Assert.Equal("/out:test.exe test.cs", csc.GenerateResponseFileContents());
         }
 
+        [Fact]
+        public void RuntimeMetadataVersionFlag()
+        {
+            var csc = new Csc();
+            csc.Sources = MSBuildUtil.CreateTaskItems("test.cs");
+            csc.RuntimeMetadataVersion = "v1234";
+            Assert.Equal("/out:test.exe /runtimemetadataversion:v1234 test.cs", csc.GenerateResponseFileContents());
+
+            csc = new Csc();
+            csc.Sources = MSBuildUtil.CreateTaskItems("test.cs");
+            csc.RuntimeMetadataVersion = null;
+            Assert.Equal("/out:test.exe test.cs", csc.GenerateResponseFileContents());
+        }
+
         [Fact]
         public void TargetTypeDll()
         {

src/Compilers/Core/MSBuildTaskTests/VbcTests.cs

@@ -73,6 +73,20 @@ public void PublicSignFlag()
             Assert.Equal("/optionstrict:custom /out:test.exe test.vb", vbc.GenerateResponseFileContents());
         }
 
+        [Fact]
+        public void RuntimeMetadataVersionFlag()
+        {
+            var vbc = new Vbc();
+            vbc.Sources = MSBuildUtil.CreateTaskItems("test.vb");
+            vbc.RuntimeMetadataVersion = "v1234";
+            Assert.Equal("/optionstrict:custom /out:test.exe /runtimemetadataversion:v1234 test.vb", vbc.GenerateResponseFileContents());
+
+            vbc = new Vbc();
+            vbc.Sources = MSBuildUtil.CreateTaskItems("test.vb");
+            vbc.RuntimeMetadataVersion = null;
+            Assert.Equal("/optionstrict:custom /out:test.exe test.vb", vbc.GenerateResponseFileContents());
+        }
+
         [Fact]
         public void TargetTypeDll()
         {