Several buildfarm mingw members are getting failures like this, when
creating conversions ... FATAL: could not load library "C:/msys/1.0/home/pgrunner/bf/root/HEAD/pgsql.3584/src/test/regress/./tmp_check/install/home/pgrunner/bf/root/HEAD/inst/lib/postgresql/utf8_and_johab.dll": Invalid access to memory location.
STATEMENT: CREATE OR REPLACE FUNCTION johab_to_utf8 (INTEGER, INTEGER, CSTRING, INTERNAL, INTEGER) RETURNS VOID AS '$libdir/utf8_and_johab', 'johab_to_utf8' LANGUAGE C STRICT;
child process exited with exit code 1
See for example
Could it have been caused by the PGDLLIMPORT/PGDLLEXPORT changes?