allocators: split allocators and pagelocker

Pagelocker is only needed for secure (usually wallet) operations, so don't make
the zero-after-free allocator depend on it.

src/Makefile.am

@@ -72,7 +72,6 @@ endif
 BITCOIN_CORE_H = \
   addrman.h \
   alert.h \
-  allocators.h \
   amount.h \
   arith_uint256.h \
   base58.h \
@@ -123,7 +122,10 @@ BITCOIN_CORE_H = \
   script/standard.h \
   serialize.h \
   streams.h \
+  support/allocators/secure.h \
+  support/allocators/zeroafterfree.h \
   support/cleanse.h \
+  support/pagelocker.h \
   sync.h \
   threadsafety.h \
   timedata.h \
@@ -233,7 +235,6 @@ univalue_libbitcoin_univalue_a_SOURCES = \
 # common: shared between bitcoind, and bitcoin-qt and non-server tools
 libbitcoin_common_a_CPPFLAGS = $(BITCOIN_INCLUDES)
 libbitcoin_common_a_SOURCES = \
-  allocators.cpp \
   arith_uint256.cpp \
   amount.cpp \
   base58.cpp \
@@ -264,6 +265,7 @@ libbitcoin_common_a_SOURCES = \
 # backward-compatibility objects and their sanity checks are linked.
 libbitcoin_util_a_CPPFLAGS = $(BITCOIN_INCLUDES)
 libbitcoin_util_a_SOURCES = \
+  support/pagelocker.cpp \
   chainparamsbase.cpp \
   clientversion.cpp \
   compat/glibc_sanity.cpp \