unneeded -DUSE_MMAP in JDK native libs builds

[Magnus Ihse Bursie]

> 2 aug. 2018 kl. 05:33 skrev Baesken, Matthias <matthias.baesken at sap.com>:
> 
> Hello I noticed that   -DUSE_MMAP  is set for these  JDK native libs, but I cannot find it in the code   (for libzip it is different there the flag shows up in the code too ) :

I've always assumed that this was used to control the behavior in some imported header files. Have you verified that this is not the case?

/Magnus

> 
> Lib-jdk.jdi.gmk  :
> 
> 32  $(eval $(call SetupJdkLibrary, BUILD_LIBDT_SHMEM, \
> ......
> 35 CFLAGS := $(CFLAGS_JDKLIB) -DUSE_MMAP, \
> 
> 
> Lib-jdk.jdwp.agent.gmk :
> 
> 30 $(eval $(call SetupJdkLibrary, BUILD_LIBDT_SOCKET, \
> ......
> 33 CFLAGS := $(CFLAGS_JDKLIB) -DUSE_MMAP \
> 
> 
> Any objections  to remove those  2    -DUSE_MMAP    settings ?
> If it is fine to remove I would prepare a  webrev .
> 
> Thanks, Matthias