build: add missing leveldb defines

Summary:
```
src/leveldb/build_detect_platform shows how upstream defines them.

These platform may not be able to fully build or run Bitcoin, but
defining all known to leveldb saves future hassle.

Now that all possible platforms are enumerated, specifying an unknown
one is an error.
```

Backport of core PR13659
https://github.com/bitcoin/bitcoin/pull/13659/files

Test Plan:
  make
  ninja

Reviewers: #bitcoin_abc, deadalnix, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D3817

configure.ac

@@ -536,10 +536,17 @@ case $host in
      CPPFLAGS="$CPPFLAGS -DMAC_OSX"
      OBJCXXFLAGS="$CXXFLAGS"
      ;;
+   *android*)
+     dnl make sure android stays above linux for hosts like *linux-android*
+     LEVELDB_TARGET_FLAGS="-DOS_ANDROID"
+     ;;
    *linux*)
      TARGET_OS=linux
      LEVELDB_TARGET_FLAGS="-DOS_LINUX"
      ;;
+   *kfreebsd*)
+     LEVELDB_TARGET_FLAGS="-DOS_KFREEBSD"
+     ;;
    *freebsd*)
      LEVELDB_TARGET_FLAGS="-DOS_FREEBSD"
      ;;
@@ -549,10 +556,17 @@ case $host in
    *netbsd*)
      LEVELDB_TARGET_FLAGS="-DOS_NETBSD"
      ;;
+   *dragonfly*)
+     LEVELDB_TARGET_FLAGS="-DOS_DRAGONFLYBSD"
+     ;;
+   *solaris*)
+     LEVELDB_TARGET_FLAGS="-DOS_SOLARIS"
+     ;;
+   *hpux*)
+     LEVELDB_TARGET_FLAGS="-DOS_HPUX"
+     ;;
    *)
-     OTHER_OS=`echo ${host_os} | awk '{print toupper($0)}'`
-     AC_MSG_WARN([Guessing LevelDB OS as OS_${OTHER_OS}, please check whether this is correct, if not add an entry to configure.ac.])
-     LEVELDB_TARGET_FLAGS="-DOS_${OTHER_OS}"
+     AC_MSG_ERROR(Cannot build leveldb for $host. Please file a bug report.)
      ;;
 esac
 

src/leveldb/CMakeLists.txt

@@ -101,6 +101,8 @@ else()
 		set(LEVELDB_OS SOLARIS)
 	elseif(${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD")
 		set(LEVELDB_OS FREEBSD)
+	elseif(${CMAKE_SYSTEM_NAME} MATCHES "KFreeBSD")
+		set(LEVELDB_OS KFREEBSD)
 	elseif(${CMAKE_SYSTEM_NAME} MATCHES "NetBSD")
 		set(LEVELDB_OS NETBSD)
 	elseif(${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
@@ -116,8 +118,7 @@ else()
 		# No idea what's the proper system name is here.
 		set(LEVELDB_OS IOS)
 	else()
-		# Unknown plateform, assume linux.
-		set(LEVELDB_OS LINUX)
+		message(FATAL_ERROR "Cannot build leveldb for ${CMAKE_SYSTEM_NAME}. Please file a bug report.")
 	endif()
 endif()