[dotnet] Only list linker flags for assemblies after we've computed them.

This means not listing per-assembly linker flags for only binding projects, but delay
it until we've computed the linker flags for all assemblies (and reflect this in
variable names as well).

dotnet/targets/Xamarin.Shared.Sdk.targets

@@ -559,9 +559,9 @@
 		<ReadItemsFromFile SessionId="$(BuildSessionId)" File="$(_LinkerItemsDirectory)/_BindingLibraryLinkWith.items" Condition="Exists('$(_LinkerItemsDirectory)/_BindingLibraryLinkWith.items')">
 			<Output TaskParameter="Items" ItemName="_BindingLibraryLinkWith" />
 		</ReadItemsFromFile>
-		<!-- Load _BindingLibraryLinkerFlags -->
-		<ReadItemsFromFile SessionId="$(BuildSessionId)" File="$(_LinkerItemsDirectory)/_BindingLibraryLinkerFlags.items" Condition="Exists('$(_LinkerItemsDirectory)/_BindingLibraryLinkerFlags.items')">
-			<Output TaskParameter="Items" ItemName="_BindingLibraryLinkerFlags" />
+		<!-- Load _AssemblyLinkerFlags -->
+		<ReadItemsFromFile SessionId="$(BuildSessionId)" File="$(_LinkerItemsDirectory)/_AssemblyLinkerFlags.items" Condition="Exists('$(_LinkerItemsDirectory)/_AssemblyLinkerFlags.items')">
+			<Output TaskParameter="Items" ItemName="_AssemblyLinkerFlags" />
 		</ReadItemsFromFile>
 		<!-- Load _BindingLibraryFrameworks -->
 		<ReadItemsFromFile SessionId="$(BuildSessionId)" File="$(_LinkerItemsDirectory)/_BindingLibraryFrameworks.items" Condition="Exists('$(_LinkerItemsDirectory)/_BindingLibraryFrameworks.items')">
@@ -851,7 +851,7 @@
 			EntitlementsInExecutable="$(_CompiledEntitlements)"
 			FrameworkRPath="$(_EmbeddedFrameworksRPath)"
 			Frameworks="@(_NativeExecutableFrameworks);@(_BindingLibraryFrameworks)"
-			LinkerFlags="@(_BindingLibraryLinkerFlags);@(_ReferencesLinkerFlags);@(_MainLinkerFlags)"
+			LinkerFlags="@(_AssemblyLinkerFlags);@(_ReferencesLinkerFlags);@(_MainLinkerFlags)"
 			LinkWithLibraries="@(_XamarinMainLibraries);@(_BindingLibraryLinkWith);@(_MainLinkWith)"
 			MinimumOSVersion="$(_MinimumOSVersion)"
 			NativeReferences="@(_FileNativeReference);@(_FrameworkNativeReference)"

tools/dotnet-linker/Steps/ComputeNativeBuildFlagsStep.cs

@@ -27,6 +27,23 @@ namespace Xamarin.Linker {
 			}
 
 			Configuration.WriteOutputForMSBuild ("_LinkerFrameworks", linkerFrameworks);
+
+			// Tell MSBuild about any additional linker flags we found
+			var linkerFlags = new List<MSBuildItem> ();
+			foreach (var asm in Configuration.Target.Assemblies) {
+				if (asm.LinkerFlags == null)
+					continue;
+				foreach (var arg in asm.LinkerFlags) {
+					var item = new MSBuildItem {
+						Include = arg,
+						Metadata = new Dictionary<string, string> {
+							{ "Assembly", asm.Identity },
+						},
+					};
+					linkerFlags.Add (item);
+				}
+			}
+			Configuration.WriteOutputForMSBuild ("_AssemblyLinkerFlags", linkerFlags);
 		}
 	}
 }

tools/dotnet-linker/Steps/ExtractBindingLibrariesStep.cs

@@ -55,23 +55,6 @@ namespace Xamarin.Linker {
 				}
 			}
 			Configuration.WriteOutputForMSBuild ("_BindingLibraryFrameworks", frameworks);
-
-			// Tell MSBuild about any additional linker flags we found
-			var linkerFlags = new List<MSBuildItem> ();
-			foreach (var asm in Configuration.Target.Assemblies) {
-				if (asm.LinkerFlags == null)
-					continue;
-				foreach (var arg in asm.LinkerFlags) {
-					var item = new MSBuildItem {
-						Include = arg,
-						Metadata = new Dictionary<string, string> {
-							{ "Assembly", asm.Identity },
-						},
-					};
-					linkerFlags.Add (item);
-				}
-			}
-			Configuration.WriteOutputForMSBuild ("_BindingLibraryLinkerFlags", linkerFlags);
 		}
 	}
 }