Revert "Update boost to 1.75, postpone other updates."

This reverts commit 8f4dd4460b.

depends/packages/boost.mk

@@ -1,10 +1,10 @@
 package=boost
-$(package)_version=1_75_0
+$(package)_version=1_74_0
 $(package)_download_path=https://dl.bintray.com/boostorg/release/$(subst _,.,$($(package)_version))/source/
 $(package)_file_name=boost_$($(package)_version).tar.bz2
-$(package)_sha256_hash=953db31e016db7bb207f11432bef7df100516eeb746843fa0486a222e3fd49cb
+$(package)_sha256_hash=83bfc1507731a0906e387fc28b7ef5417d591429e51e788417fe9ff025e116b1
 $(package)_dependencies=native_b2
-$(package)_patches=deprecated-two-arg-allocate.diff
+$(package)_patches=iostreams-106.patch signals2-noise.patch deprecated-two-arg-allocate.diff
 
 ifneq ($(host_os),darwin)
 $(package)_dependencies+=libcxx
@@ -42,6 +42,8 @@ endif
 endef
 
 define $(package)_preprocess_cmds
+  patch -p2 < $($(package)_patch_dir)/iostreams-106.patch && \
+  patch -p2 < $($(package)_patch_dir)/signals2-noise.patch && \
   patch -p2 < $($(package)_patch_dir)/deprecated-two-arg-allocate.diff && \
   echo "using $($(package)_toolset_$(host_os)) : : $($(package)_cxx) : <cflags>\"$($(package)_cflags)\" <cxxflags>\"$($(package)_cxxflags)\" <compileflags>\"$($(package)_cppflags)\" <linkflags>\"$($(package)_ldflags)\" <archiver>\"$($(package)_ar)\" <striper>\"$(host_STRIP)\"  <ranlib>\"$(host_RANLIB)\" <rc>\"$(host_WINDRES)\" : ;" > user-config.jam
 endef

depends/patches/boost/iostreams-106.patch

@@ -0,0 +1,25 @@
+From 4e76f73826fd0a7067b837e4850a9051436f5ec5 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Jean-Micha=C3=ABl=20Celerier?=
+ <jeanmichael.celerier+github@gmail.com>
+Date: Sun, 22 Dec 2019 10:26:38 +0100
+Subject: [PATCH] Fix build on windows with libc++
+
+Proposed by @SquallATF in #67
+---
+ include/boost/iostreams/detail/config/fpos.hpp | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/include/boost/iostreams/detail/config/fpos.hpp b/include/boost/iostreams/detail/config/fpos.hpp
+index c5dc6cf59..a5835421f 100644
+--- a/include/boost/iostreams/detail/config/fpos.hpp
++++ b/include/boost/iostreams/detail/config/fpos.hpp
+@@ -26,7 +26,8 @@
+ 
+ # if (defined(_YVALS) || defined(_CPPLIB_VER)) && !defined(__SGI_STL_PORT) && \
+      !defined(_STLPORT_VERSION) && !defined(__QNX__) && !defined(_VX_CPU) && !defined(__VXWORKS__) \
+-     && !((defined(BOOST_MSVC) || defined(BOOST_CLANG)) && _MSVC_STL_VERSION >= 141)
++     && !((defined(BOOST_MSVC) || defined(BOOST_CLANG)) && _MSVC_STL_VERSION >= 141) \
++     && !defined(_LIBCPP_VERSION)
+      /**/
+ 
+ #include <boost/iostreams/detail/ios.hpp>

depends/patches/boost/signals2-noise.patch

@@ -0,0 +1,23 @@
+From fd27423fea5537bc857c1fa14bb0c25b994f77b3 Mon Sep 17 00:00:00 2001
+From: Frank Mori Hess <fmh6jj@gmail.com>
+Date: Mon, 20 Jul 2020 14:17:05 -0400
+Subject: [PATCH] Fix warning about deprecated
+ boost/function_output_iterator.hpp
+
+---
+ include/boost/signals2/detail/null_output_iterator.hpp | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/include/boost/signals2/detail/null_output_iterator.hpp b/include/boost/signals2/detail/null_output_iterator.hpp
+index 9e986959..dee4373c 100644
+--- a/include/boost/signals2/detail/null_output_iterator.hpp
++++ b/include/boost/signals2/detail/null_output_iterator.hpp
+@@ -11,7 +11,7 @@
+ #ifndef BOOST_SIGNALS2_NULL_OUTPUT_ITERATOR_HPP
+ #define BOOST_SIGNALS2_NULL_OUTPUT_ITERATOR_HPP
+ 
+-#include <boost/function_output_iterator.hpp>
++#include <boost/iterator/function_output_iterator.hpp>
+ 
+ namespace boost
+ {

qa/zcash/postponed-updates.txt

@@ -7,21 +7,20 @@
 # Clang is pinned to a version that matches the Rust version.
 # This would be Clang 9, but for 4.1.0 we are using Clang 8 and postponing the upgrade.
 # libc++ is pinned to the same version as Clang.
-native_clang 8.0.1 2021-01-20
-native_clang 9.0.0 2021-01-20
-native_clang 9.0.1 2021-01-20
+native_clang 8.0.1 2020-12-01
+native_clang 9.0.0 2020-12-01
+native_clang 9.0.1 2020-12-01
 native_clang 10.0.0 2021-01-20
 native_clang 10.0.1 2021-01-20
 native_clang 11.0.0 2021-01-20
-libcxx 8.0.1 2021-01-20
-libcxx 9.0.0 2021-01-20
-libcxx 9.0.1 2021-01-20
+libcxx 8.0.1 2020-12-01
+libcxx 9.0.0 2020-12-01
+libcxx 9.0.1 2020-12-01
 libcxx 10.0.0 2021-01-20
 libcxx 10.0.1 2021-01-20
 libcxx 11.0.0 2021-01-20
 
 native_ccache 4.0 2021-01-20
-native_ccache 4.1 2021-01-20
 
 bdb 18.1.40 2021-01-20