depends: add pthread-stack-min-fix.patch for boost

This is essentially a backport but since I can't directly cherry-pick the commit from nixpkgs I've copied the patch and amended the pertinent sections in depends/packages/boost.mk.

Ma27/nixpkgs@666a863

depends/packages/boost.mk

@@ -3,7 +3,7 @@ $(package)_version=1_70_0
 $(package)_download_path=https://boostorg.jfrog.io/artifactory/main/release/1.70.0/source/
 $(package)_file_name=boost_$($(package)_version).tar.bz2
 $(package)_sha256_hash=430ae8354789de4fd19ee52f3b1f739e1fba576f0aded0897c3c2bc00fb38778
-$(package)_patches=unused_var_in_process.patch
+$(package)_patches=unused_var_in_process.patch pthread-stack-min-fix.patch
 
 define $(package)_set_vars
 $(package)_config_opts_release=variant=release
@@ -34,6 +34,7 @@ endef
 
 define $(package)_preprocess_cmds
   patch -p1 < $($(package)_patch_dir)/unused_var_in_process.patch && \
+  patch -p1 < $($(package)_patch_dir)/pthread-stack-min-fix.patch && \
   echo "using $($(package)_toolset_$(host_os)) : : $($(package)_cxx) : <cxxflags>\"$($(package)_cxxflags) $($(package)_cppflags)\" <linkflags>\"$($(package)_ldflags)\" <archiver>\"$($(package)_archiver_$(host_os))\" <striper>\"$(host_STRIP)\"  <ranlib>\"$(host_RANLIB)\" <rc>\"$(host_WINDRES)\" : ;" > user-config.jam
 endef
 

depends/patches/boost/pthread-stack-min-fix.patch

@@ -0,0 +1,15 @@
+Taken from https://github.com/conan-io/conan-center-index/pull/361/files
+
+diff --git a/include/boost/thread/pthread/thread_data.hpp b/include/boost/thread/pthread/thread_data.hpp
+index aefbeb4..bc9b136 100644
+--- a/boost/thread/pthread/thread_data.hpp
++++ b/boost/thread/pthread/thread_data.hpp
+@@ -57,7 +57,7 @@ namespace boost
+ #else
+           std::size_t page_size = ::sysconf( _SC_PAGESIZE);
+ #endif
+-#if PTHREAD_STACK_MIN > 0
++#ifdef PTHREAD_STACK_MIN
+           if (size<PTHREAD_STACK_MIN) size=PTHREAD_STACK_MIN;
+ #endif
+           size = ((size+page_size-1)/page_size)*page_size;