When doing j2se builds on windows-amd64, compiling each .c file generates a warning
cl : Command line warning D9002 : ignoring unknown option '-Zc:wchar_t-'

For example:

C:/PROGRA~1/MICROS~1/Bin/win64/x86/AMD64/cl -O1 -Zi -nologo -MD /D _STATIC_CPPLIB -Zc:wchar_t- -Fd../../../../build/windows-amd64/tmp/java/hpi/windows_threads/obj64/ -Fe../../../../build/windows-amd64/tmp/java/hpi/windows_threads/obj64/ -Fm../../../../build/windows-amd64/tmp/java/hpi/windows_threads/obj64/ -Wp64 -W3 -DWIN32 -DIAL -D_LITTLE_ENDIAN -D_AMD64_ -Damd64 -DWIN32_LEAN_AND_MEAN -I. -I../../../../build/windows-amd64/tmp/java/hpi/windows_threads/CClassHeaders -I../../../../src/windows/javavm/export -I../../../../src/share/javavm/export -I../../../../src/share/javavm/include -I../../../../src/windows/javavm/include -I../../../../src/windows/hpi/include -I../../../../src/windows/hpi/export -I../../../../src/share/hpi/include -I../../../../src/share/hpi/export -c -Fo../../../../build/windows-amd64/tmp/java/hpi/windows_threads/obj64/memory_md.obj ../../../../src/windows/hpi/src/memory_md.c
cl : Command line warning D9002 : ignoring unknown option '-Zc:wchar_t-'