Fixed failing unit tests, sorted and removed unnecessary usings in Conversions.vb

src/Compilers/CSharp/Test/Symbol/Symbols/AnonymousTypesSemanticsTests.cs

@@ -137,7 +137,8 @@ public int aa
   IVariableDeclarationStatement (1 declarations) (OperationKind.VariableDeclarationStatement) (Syntax: 'object v1 = ... };')
     IVariableDeclaration (1 variables) (OperationKind.VariableDeclaration) (Syntax: 'object v1 = ... };')
       Variables: Local_1: System.Object v1
-      Initializer: IConversionExpression (ConversionKind.Cast, Implicit) (OperationKind.ConversionExpression, Type: System.Object) (Syntax: 'new ... }')
+      Initializer: IConversionExpression (Implicit, TryCast: False, Unchecked) (OperationKind.ConversionExpression, Type: System.Object) (Syntax: 'new ... }')
+          Conversion: CommonConversion (Exists: True, IsIdentity: False, IsNumeric: False, IsReference: True, IsUserDefined: False) (MethodSymbol: null)
           Operand: IAnonymousObjectCreationExpression (OperationKind.AnonymousObjectCreationExpression, Type: <anonymous type: System.Int32 aa, System.String BB, ClassA.SSS CCC>) (Syntax: 'new ... }')
               Initializers(3):
                   ISimpleAssignmentExpression (OperationKind.SimpleAssignmentExpression, Type: System.Int32, Constant: 1) (Syntax: 'aa = 1')
@@ -157,7 +158,8 @@ public int aa
   IVariableDeclarationStatement (1 declarations) (OperationKind.VariableDeclarationStatement) (Syntax: 'object v2 = ... };')
     IVariableDeclaration (1 variables) (OperationKind.VariableDeclaration) (Syntax: 'object v2 = ... };')
       Variables: Local_1: System.Object v2
-      Initializer: IConversionExpression (ConversionKind.Cast, Implicit) (OperationKind.ConversionExpression, Type: System.Object) (Syntax: 'new ... }')
+      Initializer: IConversionExpression (Implicit, TryCast: False, Unchecked) (OperationKind.ConversionExpression, Type: System.Object) (Syntax: 'new ... }')
+          Conversion: CommonConversion (Exists: True, IsIdentity: False, IsNumeric: False, IsReference: True, IsUserDefined: False) (MethodSymbol: null)
           Operand: IAnonymousObjectCreationExpression (OperationKind.AnonymousObjectCreationExpression, Type: <anonymous type: ClassA.SSS aa, System.Double BB, <anonymous type: System.Int32 aa, System.String BB, ClassA.SSS CCC> CCC>) (Syntax: 'new ... }')
               Initializers(3):
                   ISimpleAssignmentExpression (OperationKind.SimpleAssignmentExpression, Type: ClassA.SSS) (Syntax: 'aa = new SSS()')
@@ -186,7 +188,8 @@ public int aa
   IVariableDeclarationStatement (1 declarations) (OperationKind.VariableDeclarationStatement) (Syntax: 'object v3 = new { };')
     IVariableDeclaration (1 variables) (OperationKind.VariableDeclaration) (Syntax: 'object v3 = new { };')
       Variables: Local_1: System.Object v3
-      Initializer: IConversionExpression (ConversionKind.Cast, Implicit) (OperationKind.ConversionExpression, Type: System.Object) (Syntax: 'new { }')
+      Initializer: IConversionExpression (Implicit, TryCast: False, Unchecked) (OperationKind.ConversionExpression, Type: System.Object) (Syntax: 'new { }')
+          Conversion: CommonConversion (Exists: True, IsIdentity: False, IsNumeric: False, IsReference: True, IsUserDefined: False) (MethodSymbol: null)
           Operand: IAnonymousObjectCreationExpression (OperationKind.AnonymousObjectCreationExpression, Type: <empty anonymous type>) (Syntax: 'new { }')
               Initializers(0)
   IVariableDeclarationStatement (1 declarations) (OperationKind.VariableDeclarationStatement) (Syntax: 'var v4 = new { };')
@@ -344,7 +347,8 @@ void Main()
       ISimpleAssignmentExpression (OperationKind.SimpleAssignmentExpression, Type: D1) (Syntax: 'module = (D ... ) => false)')
         Left: IPropertyReferenceExpression: D1 <anonymous type: D1 module>.module { get; } (Static) (OperationKind.PropertyReferenceExpression, Type: D1) (Syntax: 'module')
             Instance Receiver: null
-        Right: IConversionExpression (ConversionKind.CSharp, Explicit) (OperationKind.ConversionExpression, Type: D1) (Syntax: '(D1)(() => false)')
+        Right: IConversionExpression (Explicit, TryCast: False, Unchecked) (OperationKind.ConversionExpression, Type: D1) (Syntax: '(D1)(() => false)')
+            Conversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
             Operand: ILambdaExpression (Signature: lambda expression) (OperationKind.LambdaExpression, Type: null) (Syntax: '() => false')
                 IBlockStatement (1 statements) (OperationKind.BlockStatement) (Syntax: 'false')
                   IReturnStatement (OperationKind.ReturnStatement) (Syntax: 'false')
@@ -498,7 +502,8 @@ static void Test1(int x)
             Right: ILiteralExpression (OperationKind.LiteralExpression, Type: System.String, Constant: """") (Syntax: '""""')
   Arguments(1):
       IArgument (ArgumentKind.Explicit, Matching Parameter: obj) (OperationKind.Argument) (Syntax: 'new { }')
-        IConversionExpression (ConversionKind.Cast, Implicit) (OperationKind.ConversionExpression, Type: System.Object) (Syntax: 'new { }')
+        IConversionExpression (Implicit, TryCast: False, Unchecked) (OperationKind.ConversionExpression, Type: System.Object) (Syntax: 'new { }')
+          Conversion: CommonConversion (Exists: True, IsIdentity: False, IsNumeric: False, IsReference: True, IsUserDefined: False) (MethodSymbol: null)
           Operand: IAnonymousObjectCreationExpression (OperationKind.AnonymousObjectCreationExpression, Type: <empty anonymous type>) (Syntax: 'new { }')
               Initializers(0)
         InConversion: null
@@ -1011,7 +1016,8 @@ public static void Test1(int x)
   IVariableDeclarationStatement (1 declarations) (OperationKind.VariableDeclarationStatement, IsInvalid) (Syntax: 'object v1 = ... };')
     IVariableDeclaration (1 variables) (OperationKind.VariableDeclaration, IsInvalid) (Syntax: 'object v1 = ... };')
       Variables: Local_1: System.Object v1
-      Initializer: IConversionExpression (ConversionKind.Cast, Implicit) (OperationKind.ConversionExpression, Type: System.Object, IsInvalid) (Syntax: 'new ... }')
+      Initializer: IConversionExpression (Implicit, TryCast: False, Unchecked) (OperationKind.ConversionExpression, Type: System.Object, IsInvalid) (Syntax: 'new ... }')
+          Conversion: CommonConversion (Exists: True, IsIdentity: False, IsNumeric: False, IsReference: True, IsUserDefined: False) (MethodSymbol: null)
           Operand: IAnonymousObjectCreationExpression (OperationKind.AnonymousObjectCreationExpression, Type: <anonymous type: ? aa, System.String BB, SSS CCC>, IsInvalid) (Syntax: 'new ... }')
               Initializers(3):
                   ISimpleAssignmentExpression (OperationKind.SimpleAssignmentExpression, Type: ?, IsInvalid) (Syntax: 'aa = xyz')
@@ -1031,7 +1037,8 @@ public static void Test1(int x)
   IVariableDeclarationStatement (1 declarations) (OperationKind.VariableDeclarationStatement, IsInvalid) (Syntax: 'object v2 = ... };')
     IVariableDeclaration (1 variables) (OperationKind.VariableDeclaration, IsInvalid) (Syntax: 'object v2 = ... };')
       Variables: Local_1: System.Object v2
-      Initializer: IConversionExpression (ConversionKind.Cast, Implicit) (OperationKind.ConversionExpression, Type: System.Object, IsInvalid) (Syntax: 'new ... }')
+      Initializer: IConversionExpression (Implicit, TryCast: False, Unchecked) (OperationKind.ConversionExpression, Type: System.Object, IsInvalid) (Syntax: 'new ... }')
+          Conversion: CommonConversion (Exists: True, IsIdentity: False, IsNumeric: False, IsReference: True, IsUserDefined: False) (MethodSymbol: null)
           Operand: IAnonymousObjectCreationExpression (OperationKind.AnonymousObjectCreationExpression, Type: <anonymous type: SSS aa, System.Double BB, <anonymous type: ? aa, ? BB, ? CCC> CCC>, IsInvalid) (Syntax: 'new ... }')
               Initializers(3):
                   ISimpleAssignmentExpression (OperationKind.SimpleAssignmentExpression, Type: SSS, IsInvalid) (Syntax: 'aa = new SSS()')

src/Compilers/VisualBasic/Portable/Semantics/Conversions.vb

 ' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 Imports System.Collections.Immutable
-Imports System.Diagnostics
-Imports System.Linq
 Imports System.Runtime.InteropServices
-Imports Microsoft.CodeAnalysis.Collections
+Imports Microsoft.CodeAnalysis.Semantics
 Imports Microsoft.CodeAnalysis.PooledObjects
-Imports Microsoft.CodeAnalysis.Text
 Imports Microsoft.CodeAnalysis.VisualBasic.Symbols
-Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
 Imports Microsoft.CodeAnalysis.VisualBasic.Symbols.TypeSymbolExtensions
-Imports TypeKind = Microsoft.CodeAnalysis.TypeKind
-Imports Microsoft.CodeAnalysis.Semantics
 
 Namespace Microsoft.CodeAnalysis.VisualBasic