Stop passing StandardOptimizationData.mibc to crossgen2 multiple time…

…s for SPC (#67458)

Also disabled managed PGO for SourceBuild as before it was relying on no .mibc files being around to avoid passing the --mibc parameter.

eng/SourceBuild.props

@@ -38,6 +38,7 @@
       <InnerBuildArgs>$(InnerBuildArgs) /p:RuntimeOS=$(TargetRidWithoutPlatform)</InnerBuildArgs>
       <InnerBuildArgs>$(InnerBuildArgs) /p:PortableBuild=$(SourceBuildPortable)</InnerBuildArgs>
       <InnerBuildArgs>$(InnerBuildArgs) /p:BuildDebPackage=false</InnerBuildArgs>
+      <InnerBuildArgs>$(InnerBuildArgs) /p:EnableNgenOptimization=false</InnerBuildArgs>
     </PropertyGroup>
   </Target>
 

src/coreclr/crossgen-corelib.proj

@@ -84,8 +84,7 @@
       <CrossGenDllCmd>$(CrossGenDllCmd) -o:$(CoreLibOutputPath)</CrossGenDllCmd>
       <CrossGenDllCmd>$(CrossGenDllCmd) -r:$([MSBuild]::NormalizePath('$(BinDir)', 'IL', '*.dll'))</CrossGenDllCmd>
       <CrossGenDllCmd>$(CrossGenDllCmd) --targetarch:$(TargetArchitecture)</CrossGenDllCmd>
-      <MibcArgs>@(OptimizationMibcFiles->'-m:$(MergedMibcPath)', ' ')</MibcArgs>
-      <CrossGenDllCmd Condition="'$(UsingToolIbcOptimization)' != 'true' and '$(EnableNgenOptimization)' == 'true'">$(CrossGenDllCmd) $(MibcArgs) --embed-pgo-data</CrossGenDllCmd>
+      <CrossGenDllCmd Condition="'$(UsingToolIbcOptimization)' != 'true' and '$(EnableNgenOptimization)' == 'true'">$(CrossGenDllCmd) -m:$(MergedMibcPath) --embed-pgo-data</CrossGenDllCmd>
       <CrossGenDllCmd>$(CrossGenDllCmd) -O</CrossGenDllCmd>
       <CrossGenDllCmd  Condition="'$(Configuration)' == 'Debug' or '$(Configuration)' == 'Checked'">$(CrossGenDllCmd) --verify-type-and-field-layout</CrossGenDllCmd>
       <CrossGenDllCmd>$(CrossGenDllCmd) $(CoreLibInputPath)</CrossGenDllCmd>