Auto merge of #1541 - str4d:upstream-gitian-updates, r=bitcartel

Upstream gitian updates

This PR pulls in all gitian-related PRs that have been merged upstream since 0.11.2. The only ones I left out were documentation-only PRs, because we removed `doc/gitian-building.md` at some point. Here are the commits applied here, in the order shown in `git log` (ie. last to first):

- bitcoin/bitcoin#7283
  - fa42a67
  - fa58c76
- bitcoin/bitcoin#8175
  - 74c1347
- bitcoin/bitcoin#8167
  - 7e7eb27
  - ad38204
  - b676f38
- bitcoin/bitcoin#7776
  - f063863
- bitcoin/bitcoin#7424
  - a81c87f ~ we already partly applied
  - a8ce872
  - f3d3eaf ~ we already partly applied
  - 475813b
  - ~~cd27bf5~~ X we already applied
- bitcoin/bitcoin#7060
  - 3b468a0 ~ we removed doc/gitian-building.md
  - ~~99fda26~~ X we removed doc/gitian-building.md
- bitcoin/bitcoin#7251
  - fa09562
- bitcoin/bitcoin#6900
  - ~~2cecb24~~ X we removed doc/gitian-building.md
  - 957c0fd
  - 2e31d74
  - ~~0b416c6~~ X we removed QT
  - 9f251b7
- bitcoin/bitcoin#6854
  - 579b863 ~ we already partly applied

Part of #540

src/Makefile.am

@@ -79,7 +79,7 @@ LIBZCASH_H = \
   zcash/prf.h \
   zcash/util.h
 
-.PHONY: FORCE check-security
+.PHONY: FORCE check-symbols check-security
 # bitcoin core #
 BITCOIN_CORE_H = \
   addrman.h \
@@ -482,6 +482,12 @@ clean-local:
 	$(AM_V_CXX) $(OBJCXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) \
 	  $(CPPFLAGS) $(AM_CXXFLAGS) $(QT_INCLUDES) $(CXXFLAGS)  -c -o $@ $<
 
+check-symbols: $(bin_PROGRAMS)
+if GLIBC_BACK_COMPAT
+	@echo "Checking glibc back compat of [$(bin_PROGRAMS)]..."
+	$(AM_V_at) READELF=$(READELF) CPPFILT=$(CPPFILT) $(top_srcdir)/contrib/devtools/symbol-check.py < $(bin_PROGRAMS)
+endif
+
 check-security: $(bin_PROGRAMS)
 if HARDEN
 	@echo "Checking binary security of [$(bin_PROGRAMS)]..."