Rewrite libbacktrace to be all C++.

This includes removing the map_info.c source and replacing it with the
BacktraceMap class to handle all map related code.

Change all callers of libbacktrace map functionality.

Also modify the corkscrew thread code so that it doesn't need to build
the map twice (once in the corkscrew format and once in the libbacktrace
format).

Change-Id: I32865a39f83a3dd6f958fc03c2759ba47d12382e
diff --git a/libbacktrace/Android.mk b/libbacktrace/Android.mk
index d2fd79e..d729c1c 100644
--- a/libbacktrace/Android.mk
+++ b/libbacktrace/Android.mk
@@ -2,8 +2,8 @@
 
 common_src := \
 	Backtrace.cpp \
+	BacktraceMap.cpp \
 	BacktraceThread.cpp \
-	map_info.c \
 	thread_utils.c \
 
 common_cflags := \
@@ -222,7 +222,7 @@
 
 else
 LOCAL_SRC_FILES += \
-	map_info.c \
+	BacktraceMap.cpp \
 
 endif