Merge bitcoin/bitcoin#27662: build: Bump minimum supported GCC to g++-9

fa953f15bfcf95df9aa9c91e1c4b56a205f4d1ae build: Bump minimum supported GCC to g++-9 (MarcoFalke)
fa69955e741dd60dc6160e81cf223bbecd286806 ci: Bump centos:stream8 to centos:stream9 (MarcoFalke)
fa6a755d9fb22cad3d7063b21a1c8a137ae981b2 ci: Document the false positive error for g++-9 (MarcoFalke)

Pull request description:

  It is a bit frustrating to write valid C++ code only to realize that g++-8 fails to parse it later on.

  The only non-EOL operating system still shipping with g++-8 is CentOS Stream 8. I think it is reasonable for users of affected Linux distributions to:

  * Upgrade their operating system, or compiler to a supported version.
  * Alternatively, stay with a previous release of Bitcoin Core as long as it is supported.

  Fixes https://github.com/bitcoin/bitcoin/issues/27537

ACKs for top commit:
  hebasto:
    ACK fa953f15bfcf95df9aa9c91e1c4b56a205f4d1ae
  fanquake:
    ACK fa953f15bfcf95df9aa9c91e1c4b56a205f4d1ae

Tree-SHA512: b9cf7e763d3071e1e008c5010de19601d4773afe46d58cf869d3f59285c53240c739a1cd7235a5525ede1bbdf6b6cb6fb091c8fc314864a28d5b27a400bb7632

2 files changed, 3 insertions, 4 deletions

diff --git a/src/qt/addresstablemodel.cpp b/src/qt/addresstablemodel.cpp
index 0d0f1a4d15..e4689e4389 100644
--- a/src/qt/addresstablemodel.cpp
+++ b/src/qt/addresstablemodel.cpp
@@ -53,15 +53,14 @@ struct AddressTableEntryLessThan
 };
 
 /* Determine address type from address purpose */
-static AddressTableEntry::Type translateTransactionType(wallet::AddressPurpose purpose, bool isMine)
+constexpr AddressTableEntry::Type translateTransactionType(wallet::AddressPurpose purpose, bool isMine)
 {
     // "refund" addresses aren't shown, and change addresses aren't returned by getAddresses at all.
     switch (purpose) {
     case wallet::AddressPurpose::SEND: return AddressTableEntry::Sending;
     case wallet::AddressPurpose::RECEIVE: return AddressTableEntry::Receiving;
     case wallet::AddressPurpose::REFUND: return AddressTableEntry::Hidden;
-    // No default case to allow for compiler to warn
-    }
+    } // no default case, so the compiler can warn about missing cases
     assert(false);
 }
 
diff --git a/src/txrequest.cpp b/src/txrequest.cpp
index 96a3d2eeeb..40d36132de 100644
--- a/src/txrequest.cpp
+++ b/src/txrequest.cpp
@@ -69,7 +69,7 @@ struct Announcement {
     const bool m_is_wtxid : 1;
 
     /** What state this announcement is in.
-     *  This is a uint8_t instead of a State to silence a GCC warning in versions prior to 8.4 and 9.3.
+     *  This is a uint8_t instead of a State to silence a GCC warning in versions prior to 9.3.
      *  See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61414 */
     uint8_t m_state : 3;