mem/mmapstress: Default enable large file support in mmapstress tests

The tests had a lot of #ifdef checks against LARGE_FILE to switch between 64-bit and 32-bit versions of data types and system calls. Remove all that by always building these tests with _FILE_OFFSET_BITS=64 so their 32-bit compiled versions automatically use the 64-bit parts where necessary.

The testcases changed due to this are mmapstress01, mmapstress07 and mmapstress10. Their 32-bit and 64-bit built binaries were successfully built against bionic and tested on Android.

---
 testcases/kernel/mem/mmapstress/Makefile       |   4 +
 testcases/kernel/mem/mmapstress/mmapstress01.c |  79 -------------------
 testcases/kernel/mem/mmapstress/mmapstress07.c |  48 +-----------
 testcases/kernel/mem/mmapstress/mmapstress10.c | 103 -------------------------
 4 files changed, 6 insertions(+), 228 deletions(-)

index 5691f7d5d..ebe3275d0 100644
@@ -20,3 +20,7 @@ top_srcdir              ?= ../../../..
 
 include $(top_srcdir)/include/mk/testcases.mk
 include $(top_srcdir)/include/mk/generic_leaf_target.mk
+
+mmapstress01: CFLAGS += -D_FILE_OFFSET_BITS=64
+mmapstress07: CFLAGS += -D_FILE_OFFSET_BITS=64
+mmapstress10: CFLAGS += -D_FILE_OFFSET_BITS=64

2.14.1.690.gbb1197296e-goog