Make the linker relocatable.

Previously, the linker always loaded itself into the same
location in memory, which inhibited the effectiveness of Android's
ASLR implementation. Modify the linker code so it can be relocatable
and link itself at runtime.

Change-Id: Ia80273d7a00ff648b4da545f4b69debee6343968
diff --git a/linker/Android.mk b/linker/Android.mk
index 7793f8d..74c7453 100644
--- a/linker/Android.mk
+++ b/linker/Android.mk
@@ -10,27 +10,9 @@
 	dlfcn.c \
 	debugger.c
 
-ifeq ($(TARGET_ARCH),sh)
-# SH-4A series virtual address range from 0x00000000 to 0x7FFFFFFF.
-LINKER_TEXT_BASE := 0x70000100
-else
-# This is aligned to 4K page boundary so that both GNU ld and gold work.  Gold
-# actually produces a correct binary with starting address 0xB0000100 but the
-# extra objcopy step to rename symbols causes the resulting binary to be misaligned
-# and unloadable.  Increasing the alignment adds an extra 3840 bytes in padding
-# but switching to gold saves about 1M of space.
-LINKER_TEXT_BASE := 0xB0001000
-endif
+LOCAL_LDFLAGS := -shared
 
-# The maximum size set aside for the linker, from
-# LINKER_TEXT_BASE rounded down to a megabyte.
-LINKER_AREA_SIZE := 0x01000000
-
-LOCAL_LDFLAGS := -Wl,-Ttext,$(LINKER_TEXT_BASE)
-
-LOCAL_CFLAGS += -DPRELINK
-LOCAL_CFLAGS += -DLINKER_TEXT_BASE=$(LINKER_TEXT_BASE)
-LOCAL_CFLAGS += -DLINKER_AREA_SIZE=$(LINKER_AREA_SIZE)
+LOCAL_CFLAGS += -fno-stack-protector
 
 # Set LINKER_DEBUG to either 1 or 0
 #