Fix shadowing struct types by struct member names

test/libsolidity/semanticTests/errors/named_parameters_shadowing_types.sol

@@ -0,0 +1,26 @@
+pragma abicoder v2;
+
+contract C {
+    enum EnumType {A, B, C}
+
+    struct StructType {
+        uint x;
+    }
+
+    error E1(StructType StructType);
+    error E2(EnumType StructType, StructType EnumType);
+
+    function f() public {
+        revert E1({StructType: StructType(42)});
+    }
+
+    function g() public {
+        revert E2({EnumType: StructType(42), StructType: EnumType.B});
+    }
+}
+// ====
+// compileToEwasm: also
+// compileViaYul: also
+// ----
+// f() -> FAILURE, hex"33a54193", hex"000000000000000000000000000000000000000000000000000000000000002a"
+// g() -> FAILURE, hex"374b9387", hex"0000000000000000000000000000000000000000000000000000000000000001", hex"000000000000000000000000000000000000000000000000000000000000002a"

test/libsolidity/syntaxTests/enums/enum_member_shadowing.sol

@@ -0,0 +1,12 @@
+contract C {
+    struct S {
+        uint x;
+    }
+
+    enum E {E, S, C, a, f}
+
+    uint a;
+
+    function f() public pure {}
+}
+// ----

test/libsolidity/syntaxTests/errors/error_param_type_shadowed_by_builtin_type_used_as_param_name.sol

@@ -0,0 +1,5 @@
+contract C {
+    error E(int bytes, bytes x);
+}
+// ----
+// ParserError 2314: (29-34): Expected ',' but got 'bytes'

test/libsolidity/syntaxTests/errors/error_param_type_shadowed_by_param_name.sol

@@ -0,0 +1,12 @@
+contract C {
+    enum EnumType {A, B, C}
+
+    struct StructType {
+        uint x;
+    }
+
+    error E1(StructType StructType);
+    error E2(EnumType EnumType);
+    error E3(EnumType StructType, StructType EnumType);
+}
+// ----

test/libsolidity/syntaxTests/events/event_param_type_shadowed_by_param_name.sol

@@ -0,0 +1,13 @@
+contract C {
+    enum EnumType {A, B, C}
+
+    struct StructType {
+        uint x;
+    }
+
+    event E1(StructType StructType);
+    event E2(EnumType EnumType);
+    event E3(EnumType StructType, StructType EnumType);
+    event E4(StructType indexed StructType) anonymous;
+}
+// ----

test/libsolidity/syntaxTests/structs/member_type_eq_name.sol

@@ -3,4 +3,4 @@ contract C {
   function f(function(S memory) external) public {}
 }
 // ----
-// TypeError 5172: (25-26): Name has to refer to a struct, enum or contract.
+// DeclarationError 7920: (25-26): Identifier not found or not unique.

test/libsolidity/syntaxTests/structs/member_type_eq_name_2.sol

@@ -0,0 +1,6 @@
+contract C {
+    enum E {a, b, c}
+    struct S {E X; uint E;}
+    struct T {E T; uint E;}
+    struct U {E E;}
+}