"make hotspot" builds test .obj files first

[Ioi Lam]

My windows build is very slow, and it spends the first few minutes 
compiling test_xxx.obj files.

Is it possible to build the HotSpot VM .obj files first?

Thanks
- Ioi

$ time make hotspot LOG=info
Generating main target list
Running make as 'make LOG=info hotspot'
Building target 'hotspot' in configuration 'windows-x64-slowdebug'
Building JVM variant 'server' with features 'cds compiler1 compiler2 
epsilongc g1gc jfr jni-check jvmci jvmti management oracle-src 
parallelgc serialgc services vm-structs zgc'
Updating support/modules_libs/java.base/server/jvm.dll due to 6 file(s)
Compiling BUILD_GTEST_LIBJVM_pch.cpp (for jvm.dll)
Compiling BUILD_LIBJVM_pch.cpp (for jvm.dll)
Compiling gtestMain.cpp (for jvm.dll)
Compiling logTestFixture.cpp (for jvm.dll)
Compiling metaspaceGtestCommon.cpp (for jvm.dll)
Compiling metaspaceGtestContexts.cpp (for jvm.dll)
Compiling test_AltHashing.cpp (for jvm.dll)
Compiling test_ThreadsListHandle.cpp (for jvm.dll)
Compiling test_adaptiveSampler.cpp (for jvm.dll)
Compiling test_align.cpp (for jvm.dll)
Compiling test_allocationGuard.cpp (for jvm.dll)
Compiling test_arena.cpp (for jvm.dll)
Compiling test_arenagrowthpolicy.cpp (for jvm.dll)