MSVC builds: Ensure /LTCG when necessary

gtk3-demo, gtk3-demo-application and gtk3-icon-factory are built using
/opt:noref as they use GResources without --manual-register, meaning that
flag is used to avoid the linker from optimizing out the GResource items
for release builds.

Visual Studio 2015 changed its default link-time code generation setting
to /LTCG:incremental, which would cause problems as it will cause the
linker to optimize out the GResource items from the compiled code, so fix
this by enforcing /LTCG for these three items.

build/win32/vs10/gtk3-demo-application.vcxprojin

@@ -107,6 +107,7 @@
       <SubSystem>Console</SubSystem>
       <OptimizeReferences>false</OptimizeReferences>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
       <TargetMachine>MachineX86</TargetMachine>
     </Link>
   </ItemDefinitionGroup>
@@ -151,6 +152,7 @@
       <SubSystem>Console</SubSystem>
       <OptimizeReferences>false</OptimizeReferences>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
       <TargetMachine>MachineX64</TargetMachine>
     </Link>
   </ItemDefinitionGroup>

build/win32/vs10/gtk3-demo.vcxprojin

@@ -96,6 +96,31 @@
       <TargetMachine>MachineX86</TargetMachine>
     </Link>
   </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <AdditionalIncludeDirectories>..\..\..\gdk;..\..\..\gtk;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>$(GtkPrefixDefine);%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <CompileAs>CompileAsC</CompileAs>
+    </ClCompile>
+    <Link>
+      <AdditionalDependencies>%(AdditionalDependencies)</AdditionalDependencies>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <SubSystem>Console</SubSystem>
+      <FunctionLevelLinking>false</FunctionLevelLinking>
+      <OptimizeReferences>false</OptimizeReferences>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <RandomizedBaseAddress>false</RandomizedBaseAddress>
+      <DataExecutionPrevention>
+      </DataExecutionPrevention>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
+      <TargetMachine>MachineX86</TargetMachine>
+    </Link>
+  </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
     <ClCompile>
       <Optimization>Disabled</Optimization>
@@ -120,30 +145,6 @@
       <TargetMachine>MachineX64</TargetMachine>
     </Link>
   </ItemDefinitionGroup>
-  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
-    <ClCompile>
-      <AdditionalIncludeDirectories>..\..\..\gdk;..\..\..\gtk;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>$(GtkPrefixDefine);%(PreprocessorDefinitions)</PreprocessorDefinitions>
-      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
-      <PrecompiledHeader>
-      </PrecompiledHeader>
-      <WarningLevel>Level3</WarningLevel>
-      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
-      <CompileAs>CompileAsC</CompileAs>
-    </ClCompile>
-    <Link>
-      <AdditionalDependencies>%(AdditionalDependencies)</AdditionalDependencies>
-      <GenerateDebugInformation>true</GenerateDebugInformation>
-      <SubSystem>Console</SubSystem>
-      <FunctionLevelLinking>false</FunctionLevelLinking>
-      <OptimizeReferences>false</OptimizeReferences>
-      <EnableCOMDATFolding>true</EnableCOMDATFolding>
-      <RandomizedBaseAddress>false</RandomizedBaseAddress>
-      <DataExecutionPrevention>
-      </DataExecutionPrevention>
-      <TargetMachine>MachineX86</TargetMachine>
-    </Link>
-  </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
     <ClCompile>
       <AdditionalIncludeDirectories>..\..\..\gdk;..\..\..\gtk;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
@@ -165,6 +166,7 @@
       <RandomizedBaseAddress>false</RandomizedBaseAddress>
       <DataExecutionPrevention>
       </DataExecutionPrevention>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
       <TargetMachine>MachineX64</TargetMachine>
     </Link>
   </ItemDefinitionGroup>

build/win32/vs10/gtk3-icon-browser.vcxprojin

@@ -109,6 +109,7 @@
       <SubSystem>Console</SubSystem>
       <OptimizeReferences>false</OptimizeReferences>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
       <TargetMachine>MachineX86</TargetMachine>
     </Link>
   </ItemDefinitionGroup>
@@ -155,6 +156,7 @@
       <SubSystem>Console</SubSystem>
       <OptimizeReferences>false</OptimizeReferences>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
       <TargetMachine>MachineX64</TargetMachine>
     </Link>
   </ItemDefinitionGroup>