Fix Boost compilation on macOS

depends/packages/boost.mk

@@ -3,6 +3,7 @@ $(package)_version=1_70_0
 $(package)_download_path=https://dl.bintray.com/boostorg/release/1.70.0/source
 $(package)_file_name=$(package)_$($(package)_version).tar.bz2
 $(package)_sha256_hash=430ae8354789de4fd19ee52f3b1f739e1fba576f0aded0897c3c2bc00fb38778
+$(package)_patches=darwin.diff
 
 define $(package)_set_vars
 $(package)_config_opts_release=variant=release
@@ -26,6 +27,7 @@ $(package)_cxxflags_freebsd=-fPIC
 endef
 
 define $(package)_preprocess_cmds
+  patch -p1 < $($(package)_patch_dir)/darwin.diff
 endef
 
 define $(package)_config_cmds

depends/patches/boost/darwin.diff

@@ -0,0 +1,27 @@
+diff --git a/darwin.jam b/darwin.jam
+index 8d47741..641d8bb 100644
+--- a/tools/build/src/tools/darwin.jam
++++ b/tools/build/src/tools/darwin.jam
+@@ -138,14 +138,14 @@ rule init ( version ? : command * : options * : requirement * )
+     common.handle-options darwin : $(condition) : $(command) : $(options) ;
+     
+     # - GCC 4.0 and higher in Darwin does not have -fcoalesce-templates.
+-    if $(real-version) < "4.0.0"
+-    {
+-        flags darwin.compile.c++ OPTIONS $(condition) : -fcoalesce-templates ;
+-    }
++#    if $(real-version) < "4.0.0"
++#    {
++#        flags darwin.compile.c++ OPTIONS $(condition) : -fcoalesce-templates ;
++#    }
+     # - GCC 4.2 and higher in Darwin does not have -Wno-long-double.
+-    if $(real-version) < "4.2.0"
+-    {
+-        flags darwin.compile OPTIONS $(condition) : -Wno-long-double ;
+-    }
++#    if $(real-version) < "4.2.0"
++#    {
++#        flags darwin.compile OPTIONS $(condition) : -Wno-long-double ;
++#    }
+     # - GCC on Darwin with -pedantic, suppress unsupported long long warning
+     flags darwin.compile OPTIONS $(condition)/<warnings>all : -Wno-long-long ;