build: fix win32 static linking after libtool merge

Libtool eats the -static flag rather than passing it along to the compiler. To
get the same effect, -all-static is used instead.

configure.ac

@@ -193,10 +193,13 @@ case $host in
      AC_CHECK_LIB([iphlpapi],      [main],, AC_MSG_ERROR(lib missing))
      AC_CHECK_LIB([crypt32],      [main],, AC_MSG_ERROR(lib missing))
 
-     AX_CHECK_LINK_FLAG([[-static]],[LDFLAGS="$LDFLAGS -static"])
      AX_CHECK_LINK_FLAG([[-static-libgcc]],[LDFLAGS="$LDFLAGS -static-libgcc"])
      AX_CHECK_LINK_FLAG([[-static-libstdc++]],[LDFLAGS="$LDFLAGS -static-libstdc++"])
 
+     # -static is interpreted by libtool, where it has a different meaning.
+     # In libtool-speak, it's -all-static.
+     AX_CHECK_LINK_FLAG([[-static]],[LDFLAGS="$LDFLAGS -static"; LIBTOOL_LDFLAGS="$LIBTOOL_LDFLAGS -all-static"])
+
      AC_PATH_PROG([MAKENSIS], [makensis], none)
      if test x$MAKENSIS = xnone; then
        AC_MSG_WARN("makensis not found. Cannot create installer.")
@@ -698,6 +701,7 @@ AC_SUBST(CLIENT_VERSION_IS_RELEASE, _CLIENT_VERSION_IS_RELEASE)
 AC_SUBST(COPYRIGHT_YEAR, _COPYRIGHT_YEAR)
 
 
+AC_SUBST(LIBTOOL_LDFLAGS)
 AC_SUBST(USE_UPNP)
 AC_SUBST(USE_QRCODE)
 AC_SUBST(INCLUDES)

src/Makefile.am

@@ -1,5 +1,5 @@
 AM_CPPFLAGS =  $(INCLUDES)
-AM_LDFLAGS = $(PTHREAD_CFLAGS)
+AM_LDFLAGS = $(PTHREAD_CFLAGS) $(LIBTOOL_LDFLAGS)
 
 if USE_LIBSECP256K1
 secp256k1/libsecp256k1.la: $(wildcard secp256k1/src/*) $(wildcard secp256k1/include/*)