"String table overflow" when building test-6.0.0 windows binaries with gitian

[abitmore]

Build Error Description

Got "String table overflow" error on wallet_voting.cpp when building test-6.0.0 windows binaries with gitian:

CMakeFiles/graphene_wallet.dir/wallet_voting.cpp.obj : ... : string table overflow at offset 10002456
/tmp/ccBdPcId.s: Assembler messages:
/tmp/ccBdPcId.s: Fatal error: can't close CMakeFiles/graphene_wallet.dir/wallet_voting.cpp.obj: File too big
libraries/wallet/CMakeFiles/graphene_wallet.dir/build.make:375: recipe for target 'libraries/wallet/CMakeFiles/graphene_wallet.dir/wallet_voting.cpp.obj' failed

Note: this issue is similar to #2003 .

Build Environment
Details about the build environment, including the relevant required libraries. Much of this information can be found in the CMakeFiles/CMakeOutput.log.

• Host OS: Ubuntu 18.04 LTS (as used by https://github.com/bitshares/bitshares-gitian/ )
• Host Physical RAM 16GB
• Source Branch/Tag: test-6.0.0 (5869dc5)
• OpenSSL Version: 1.1.1i
• Boost Version: 1.69.0
• C++ Compiler: gcc- (mingw)

Steps To Reproduce

• Prepare https://github.com/bitshares/bitshares-gitian/ environment
• run-gitian -b -O win test-6.0.0

[abitmore]

It turns out that MinGW build works with Ubuntu 20.04, but does not work with Ubuntu 18.04 .