Fix remaining dip1000 deprecations

src/std/io/internal/iovec.d

@@ -20,7 +20,7 @@ struct TempIOVecs
 @trusted @nogc pure nothrow:
     enum iovec* useStack = () @trusted{ return cast(iovec*) size_t.max; }();
 
-    this(return scope inout(ubyte[])[] bufs)
+    this(return scope inout(ubyte[])[] bufs) scope
     {
         import core.exception : onOutOfMemoryError;
 

src/std/io/internal/string.d

@@ -13,13 +13,13 @@ enum isStringLike(S) = (isInputRange!S && !isInfinite!S && isSomeChar!(ElementEn
 struct String
 {
 nothrow pure @safe @nogc:
-    this(const char[] s) @trusted
+    this(scope const(char)[] s) scope @trusted
     {
         ptr = s.ptr;
         len = cast(uint) s.length;
     }
 
-    this(S)(scope S s) if (isStringLike!S)
+    this(S)(scope S s) scope if (isStringLike!S)
     {
         this ~= s;
     }
@@ -102,7 +102,7 @@ nothrow pure @safe @nogc:
     }
 
     ///
-    String clone() scope
+    String clone() return scope //@trusted
     {
         return String(this[]);
     }
@@ -121,7 +121,7 @@ nothrow pure @safe @nogc:
 
 private:
 
-    this(const(char)* ptr, uint len, uint cap)
+    this(const(char)* ptr, uint len, uint cap) scope
     {
         this.ptr = ptr;
         this.len = len;

src/std/io/net/socket.d

@@ -613,7 +613,7 @@ package(std.io.net):
 private:
     import std.typecons : Tuple;
 
-    this(return scope Driver.SOCKET s, bool cod) @trusted pure nothrow
+    this(scope Driver.SOCKET s, bool cod) @trusted pure nothrow
     {
         this.s = s;
         this.closeOnDestroy = cod;

src/std/io/package.d

@@ -149,7 +149,7 @@ class IOObject(IO) : IOInterfaces!IO
 {
 @safe @nogc:
     /// construct class from `io`
-    this(IO io)
+    this(IO io) scope
     {
         this.io = io.move;
     }