Removed private field visibility rule

Removed the HasPrivateAccessorOnFieldNamesFormattingRule.  It did a
subset of the work that ExplicitVisibilityRule does.

Author: jaredpar

src/Microsoft.DotNet.CodeFormatting.Tests/Microsoft.DotNet.CodeFormatting.Tests.csproj

@@ -111,7 +111,6 @@
     <Compile Include="Rules\HasNewLineBeforeFirstUsingFormattingRuleTests.cs" />
     <Compile Include="Rules\HasNoNewLineAfterOpenBraceFormattingRuleTests.cs" />
     <Compile Include="Rules\HasNoNewLineBeforeEndBraceFormattingRuleTests.cs" />
-    <Compile Include="Rules\HasPrivateAccessorOnFieldNamesFormattingRuleTests.cs" />
     <Compile Include="Rules\HasUnderScoreInPrivateFieldNamesFormattingRuleTests.cs" />
     <Compile Include="Rules\UsesXunitForTestsFormattingRuleTests.cs" />
   </ItemGroup>

src/Microsoft.DotNet.CodeFormatting.Tests/Rules/ExplicitVisibilityRuleTests.cs

@@ -236,5 +236,35 @@ internal S(int p1, int p2) { }
 
             Verify(text, expected, runFormatter: false);
         }
+
+        [Fact]
+        public void TestPrivateFields()
+        {
+            var text = @"
+using System;
+class T
+{
+    static int x;
+    private static int y;
+    // some trivia
+    protected internal int z;
+    // some trivia
+    int k = 1, s = 2;
+    // some trivia
+}";
+            var expected = @"
+using System;
+internal class T
+{
+    private static int x;
+    private static int y;
+    // some trivia
+    protected internal int z;
+    // some trivia
+    private int k = 1, s = 2;
+    // some trivia
+}";
+            Verify(text, expected);
+        }
     }
 }

src/Microsoft.DotNet.CodeFormatting.Tests/Rules/HasPrivateAccessorOnFieldNamesFormattingRuleTests.cs

@@ -95,7 +95,6 @@
     <Compile Include="Rules\HasNoNewLineAfterOpenBraceFormattingRule.cs" />
     <Compile Include="Rules\HasNoNewLineBeforeEndBraceFormattingRule.cs" />
     <Compile Include="Rules\HasNoCustomCopyrightHeaderFormattingRule.cs" />
-    <Compile Include="Rules\HasPrivateAccessorOnFieldNamesFormattingRule.cs" />
     <Compile Include="Rules\HasUnderScoreInPrivateFieldNamesFormattingRule.cs" />
     <Compile Include="Rules\HasUsingsOutsideOfNamespaceFormattingRule.cs" />
     <Compile Include="Rules\IsFormattedFormattingRule.cs" />

src/Microsoft.DotNet.CodeFormatting/Microsoft.DotNet.CodeFormatting.csproj

@@ -11,7 +11,7 @@
 
 namespace Microsoft.DotNet.CodeFormatting.Rules
 {
-    [RuleOrder(12)]
+    [RuleOrder(9)]
     internal sealed class ExplicitVisibilityRule : IFormattingRule
     {
         private sealed class VisibilityRewriter : CSharpSyntaxRewriter