Improve consumption of NativeAOT linker flags (#18835)

Fixes #18819

dotnet/targets/Xamarin.Shared.Sdk.targets

@@ -1285,77 +1285,12 @@
 			<TrimmerRootAssembly Include="@(_TrimmerRootAssemblyButOnlyIntermediateAssembly->'%(Filename)')" />
 		</ItemGroup>
 
-		<!--
-
-			Collect all the native linker args ILC would have used and use
-			them ourselves when we link natively.
-
-			Unfortunately there's a major difference between LinkerArgs (as
-			used by ILC) and our _CustomLinkerFlags: ILC splits on space in
-			LinkerArg, while we quote (when necessary) the items in
-			_CustomLinkerFlags.
-
-			Example:
-
-				<LinkerArg Include="-framework UIKit" />
-
-					ILC will pass that as two separate arguments to the native
-					compiler
-
-				<_CustomLinkFlags Include="-framework UIKit" />
-
-					We'll pass that as a single argument ('-framework UIKit')
-					to the native compiler (which the native compiler doesn't
-					like)
-
-			So we need to convert the list of space-separated items in
-			LinkerArg to space-preserved items in _CustomLinkFlags.
-
-			How to do this in MSBuild is somewhat non-obvious: first we
-			convert the LinkerArg item group to a property where every item is
-			separated by a semi-colon, and where we've also replaced spaces by
-			semi-colons. This means we have a property where every flag we
-			want is separated by a semi-colon. Then we split on the property
-			string on a semi-colon and add those items to the _CustomLinkFlags
-			item group.
-
-			Note: this means ILC doesn't support linker flags with spaces in them.
-
-			Additionally, the LinkerArg item group are actually passed to the
-			native compiler by the NativeAOT build tasks, not the native
-			linker. This means they might contain wrapped linker arguments:
-			'-Wl,...', which the compiler understands, but not the linker.
-			Thus we need to unwrap the (compiler) arguments in LinkerArgs to
-			be actual linker arguments. Also note that there can be multiple
-			linker arguments passed using a single compiler argument, and
-			those are separated by a comma: "-Wl,-linkerarg1,-linkerarg2", so
-			we need to split those into multiple linker arguments as well. And
-			to make things even more complicated, there may be quotes as well:
-			<LinkerArg>'-Wl,-linkerarg1,-linkerarg2'</LinkerArg>.
-
-		-->
-		<PropertyGroup>
-			<_LinkerArgsSplitBySemiColon>@(LinkerArg->Replace(' ',';'))</_LinkerArgsSplitBySemiColon>
-		</PropertyGroup>
 		<ItemGroup>
-			<_AllLinkerArgs Include="$(_LinkerArgsSplitBySemiColon.Split(';'))" />
+			<!-- Collect extra native linker flags ILC would have used -->
-			<_LinkerArgsWhichAreReallyCompilerArgs Include="@(_AllLinkerArgs)" Condition="$([System.String]::new('%(Identity)').StartsWith('-Wl,'))">
+			<_CustomLinkFlags Include="@(NativeLibrary)" />
-				<TransformedArgument>$([System.String]::new('%(Identity)').Substring(4))</TransformedArgument>
+			<_CustomLinkFlags Include="@(NativeSystemLibrary->'-l%(Identity)')" />
-			</_LinkerArgsWhichAreReallyCompilerArgs>
+			<_CustomLinkFlags Include="@(NativeFramework->'-Wl,-framework,%(Identity)')" />
-			<!-- Handle quoted arguments: <LinkerArg>'-Wl,-linkerarg'</LinkerArg> -->
+			<_CustomLinkFlags Include="@(ExtraLinkerArg->'-Wl,%(Identity)')" />
-			<_LinkerArgsWhichAreReallyCompilerArgs Include="@(_AllLinkerArgs)" Condition="$([System.String]::new('%(Identity)').StartsWith('%27-Wl,')) And $([System.String]::new('%(Identity)').EndsWith('%27'))">
-				<TransformedArgument>$([System.String]::new('%(Identity)').Substring(5, $([MSBuild]::Subtract($([System.String]::new('%(Identity)').Length), 6))))</TransformedArgument>
-			</_LinkerArgsWhichAreReallyCompilerArgs>
-			<_CompilerArgsTransformedToLinkerArgs Include="@(_LinkerArgsWhichAreReallyCompilerArgs->'%(TransformedArgument)')" />
-		</ItemGroup>
-		<PropertyGroup>
-			<_CompilerArgsTransformedToLinkerArgsSplitByComma>@(_CompilerArgsTransformedToLinkerArgs->Replace(',',';'))</_CompilerArgsTransformedToLinkerArgsSplitByComma>
-		</PropertyGroup>
-		<ItemGroup>
-			<_AllLinkerArgs Remove="@(_LinkerArgsWhichAreReallyCompilerArgs)" />
-			<_AllLinkerArgs Include="$(_CompilerArgsTransformedToLinkerArgsSplitByComma.Split(';'))" />
-
-			<_CustomLinkFlags Include="@(_AllLinkerArgs)" />
 		</ItemGroup>
 
 		<ItemGroup>