[LyX/master] Revert "Remove 3rdparty/boost/Makefile.am"

[Jean-Marc Lasgouttes]

commit f53a205720bce9b42236d43e7535e1974dd21fa9
Author: Jean-Marc Lasgouttes <lasgouttes at lyx.org>
Date:   Sun Nov 29 19:14:40 2020 +0100

    Revert "Remove 3rdparty/boost/Makefile.am"
    
    This reverts commit 125ed160d625368520074f2898c0487d30d46b98.
---
 3rdparty/boost/Makefile.am |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/3rdparty/boost/Makefile.am b/3rdparty/boost/Makefile.am
new file mode 100644
index 0000000..ff8fa4b
--- /dev/null
+++ b/3rdparty/boost/Makefile.am
@@ -0,0 +1,12 @@
+include $(top_srcdir)/config/common.am
+
+EXTRA_DIST = boost \
+	CMakeLists.txt \
+	LICENSE_1_0.txt \
+	libs/CMakeLists.txt \
+	libs/regex/CMakeLists.txt \
+	libs/regex/src/CMakeLists.txt
+
+AM_CPPFLAGS += -DBOOST_USER_CONFIG="<config.h>" 
+AM_CPPFLAGS +=  $(BOOST_INCLUDES)
+