pcache test failing on Windows with app crash

I think I know why pcache is failing, and it must have started after a Windows update or sthg: it crashes natively due to the use-after-free messing w/ Windows heap, and we run pcache test w/o leak tracking which I guess must turn off replace_malloc.

```
05:28 PM ~/drmemory/build_suite/build_drmemory-dbg-32
% ctest -V -R pcache
UpdateCTestConfiguration from :D:/derek/drmemory/build_suite/build_drmemory-dbg-32/DartConfiguration.tcl
UpdateCTestConfiguration from :D:/derek/drmemory/build_suite/build_drmemory-dbg-32/DartConfiguration.tcl
Test project D:/derek/drmemory/build_suite/build_drmemory-dbg-32
Constructing a list of tests
Done constructing a list of tests
Checking test dependency graph...
Checking test dependency graph end
test 68
Start 68: pcache

68: Test command: "C:\Program Files (x86)\CMake 2.8\bin\cmake.exe" "-D" "cmd:STRING=.././bin/drmemory.exe@-debug@-dr_debug@-dr@{DRMEMORY_CTEST_DR_DIR}/..@-batch@-dr_ops@-dumpcore_mask@@0x87fd@@-stderr_mask@@15@@-msgbox_mask@@0@@-no_use_persisted@@-no_coarse_disk_merge@@-no_coarse_lone_merge@-callstack_style@0x27@-no_results_to_stderr@-no_check_uninitialized@-no_count_leaks@-persist_code@--@./pcache.exe" "-D" "TOOL_DR_HEAPSTAT:BOOL=OFF" "-D" "outpat:STRING={DRMEMORY_CTEST_SRC_DIR}/addronly.out" "-D" "respat:STRING={DRMEMORY_CTEST_SRC_DIR}/addronly.res" "-D" "nudge:STRING=.././bin/drmemory.exe@-debug@-dr_debug@-dr@{DRMEMORY_CTEST_DR_DIR}/..@-batch" "-D" "VMKERNEL:BOOL=OFF" "-D" "USE_DRSYMS:BOOL=ON" "-D" "X64:BOOL=OFF" "-D" "toolbindir:STRING={DRMEMORY_CTEST_DR_DIR}/../bin32" "-D" "DRMEMORY_CTEST_SRC_DIR:STRING=D:/derek/drmemory/git/src/tests" "-D" "DRMEMORY_CTEST_DR_DIR:STRING=D:/derek/drmemory/build_suite/build_drmemory-dbg-32/dynamorio/cmake" "-D" "CMAKE_SYSTEM_VERSION:STRING=6.1" "-D" "exit_code:STRING=0" "-D" "path_append:STRING=" "-D" "postcmd:STRING=" "-P" "./runtest.cmake"
68: Test timeout computed to be: 9.99988e+006
68: STDOUT:
68: STDERR:
68:
68: ~~Dr.M~~ Dr. Memory version 1.8.16704
68: ~~Dr.M~~ Running "./pcache.exe"
68: ~~Dr.M~~ WARNING: application exited with abnormal code 0xc0000005
```