Allow building arm64 using VS2017 tools

VS2017 now includes ARM64 compilers. Change the build scripts so
that the normal VC tools path is used for the builds for ARM64.
However, if -toolset_dir is passed, then use the specified tools,
as before.

build-test.cmd

@@ -87,7 +87,7 @@ if /i "%1" == "-help" goto Usage
 if /i "%1" == "x64"                   (set __BuildArch=x64&set __VCBuildArch=x86_amd64&set processedArgs=!processedArgs! %1&shift&goto Arg_Loop)
 if /i "%1" == "x86"                   (set __BuildArch=x86&set __VCBuildArch=x86&set processedArgs=!processedArgs! %1&shift&goto Arg_Loop)
 if /i "%1" == "arm"                   (set __BuildArch=arm&set __VCBuildArch=x86_arm&set processedArgs=!processedArgs! %1&shift&goto Arg_Loop)
-if /i "%1" == "arm64"                 (set __BuildArch=arm64&set processedArgs=!processedArgs! %1&shift&goto Arg_Loop)
+if /i "%1" == "arm64"                 (set __BuildArch=arm64&set __VCBuildArch=x86_arm64&set processedArgs=!processedArgs! %1&shift&goto Arg_Loop)
 
 if /i "%1" == "debug"                 (set __BuildType=Debug&set processedArgs=!processedArgs! %1&shift&goto Arg_Loop)
 if /i "%1" == "release"               (set __BuildType=Release&set processedArgs=!processedArgs! %1&shift&goto Arg_Loop)
@@ -126,9 +126,11 @@ call                                 "%__VSToolsRoot%\VsDevCmd.bat"
 
 set __RunArgs=-BuildOS=%__BuildOS% -BuildType=%__BuildType% -BuildArch=%__BuildArch%
 
-rem arm64 builds currently use private toolset which has not been released yet
-REM TODO, remove once the toolset is open.
-if /i "%__BuildArch%" == "arm64" call :PrivateToolSet
+if defined __ToolsetDir (
+    rem arm64 builds currently use private toolset which has not been released yet
+    REM TODO, remove once the toolset is open.
+    call :PrivateToolSet
+)
 
 echo %__MsgPrefix%Commencing CoreCLR repo test build
 
@@ -185,8 +187,8 @@ REM ============================================================================
 echo %__MsgPrefix%Commencing build of native test components for %__BuildArch%/%__BuildType%
 
 if defined __ToolsetDir (
- echo %__MsgPrefix%ToolsetDir is defined to be :%__ToolsetDir%
- goto GenVSSolution :: Private ToolSet is Defined
+    echo %__MsgPrefix%ToolsetDir is defined to be %__ToolsetDir%
+    goto GenVSSolution :: Private ToolSet is Defined
 )
 
 :: Set the environment for the native build
@@ -490,7 +492,7 @@ exit /b 1
 
 :PrivateToolSet
 
-echo %__MsgPrefix% Setting Up the usage of __ToolsetDir:%__ToolsetDir%
+echo %__MsgPrefix%Setting up the usage of __ToolsetDir:%__ToolsetDir%
 
 if /i "%__ToolsetDir%" == "" (
     echo %__MsgPrefix%Error: A toolset directory is required for the Arm64 Windows build. Use the toolset_dir argument.

build.cmd

@@ -368,10 +368,10 @@ if %__BuildNative% EQU 1 (
 
     echo %__MsgPrefix%Commencing build of native components for %__BuildOS%.%__BuildArch%.%__BuildType%
 
-    set nativePlatfromArgs=-platform=%__BuildArch%
-    if /i "%__BuildArch%" == "arm64" ( set nativePlatfromArgs=-useEnv )
+    set __NativePlatformArgs=-platform=%__BuildArch%
+    if not "%__ToolsetDir%" == "" ( set __NativePlatformArgs=-useEnv )
 
-    if /i "%__BuildArch%" == "arm64" (
+    if not "%__ToolsetDir%" == "" (
         rem arm64 builds currently use private toolset which has not been released yet
         REM TODO, remove once the toolset is open.
         call :PrivateToolSet
@@ -387,6 +387,12 @@ if %__BuildNative% EQU 1 (
         REM Make CMake pick the highest installed version in the 10.0.* range
         set ___SDKVersion="-DCMAKE_SYSTEM_VERSION=10.0"
     )
+    if /i "%__BuildArch%" == "arm64" (
+        set __VCBuildArch=x86_arm64
+
+        REM Make CMake pick the highest installed version in the 10.0.* range
+        set ___SDKVersion="-DCMAKE_SYSTEM_VERSION=10.0"
+    )
 
     echo %__MsgPrefix%Using environment: "%__VCToolsRoot%\vcvarsall.bat" !__VCBuildArch!
     call                                 "%__VCToolsRoot%\vcvarsall.bat" !__VCBuildArch!
@@ -425,7 +431,7 @@ if %__BuildNative% EQU 1 (
     set __MsbuildWrn=/flp1:WarningsOnly;LogFile=!__BuildWrn!
     set __MsbuildErr=/flp2:ErrorsOnly;LogFile=!__BuildErr!
 
-    @call %__ProjectDir%\run.cmd build -Project=%__IntermediatesDir%\install.vcxproj -MsBuildLog=!__MsbuildLog! -MsBuildWrn=!__MsbuildWrn! -MsBuildErr=!__MsbuildErr! -configuration=%__BuildType% %nativePlatfromArgs% %__RunArgs% -ExtraParameters="/p:ForceImportBeforeCppTargets=%__ProjectDir%/clr.nativebuild.props /m:2" %__UnprocessedBuildArgs%
+    @call %__ProjectDir%\run.cmd build -Project=%__IntermediatesDir%\install.vcxproj -MsBuildLog=!__MsbuildLog! -MsBuildWrn=!__MsbuildWrn! -MsBuildErr=!__MsbuildErr! -configuration=%__BuildType% %__NativePlatformArgs% %__RunArgs% -ExtraParameters="/p:ForceImportBeforeCppTargets=%__ProjectDir%/clr.nativebuild.props /m:2" %__UnprocessedBuildArgs%
 
     if not !errorlevel! == 0 (
         echo %__MsgPrefix%Error: native component build failed. Refer to the build log files for details:
@@ -665,7 +671,7 @@ if %__BuildTests% EQU 1 (
 
     rem arm64 builds currently use private toolset which has not been released yet
     REM TODO, remove once the toolset is open.
-    if /i "%__BuildArch%" == "arm64" call :PrivateToolSet
+    if not "%__ToolsetDir%" == "" call :PrivateToolSet
 
     set NEXTCMD=call %__ProjectDir%\build-test.cmd %__BuildArch% %__BuildType% %__UnprocessedBuildArgs%
     echo %__MsgPrefix%!NEXTCMD!
@@ -839,7 +845,7 @@ exit /b 1
 
 :PrivateToolSet
 
-echo %__MsgPrefix% Setting Up the usage of __ToolsetDir:%__ToolsetDir%
+echo %__MsgPrefix%Setting up the usage of __ToolsetDir:%__ToolsetDir%
 
 if /i "%__ToolsetDir%" == "" (
     echo %__MsgPrefix%Error: A toolset directory is required for the Arm64 Windows build. Use the toolset_dir argument.