Note that the minimum supported gcc (on Windows) is 3.4.5

Earlier versions (from www.mingw.org, at least) will build perl, but have
a linker bug that causes various tests to fail due to problems with
SDBM_File.dll. See perl #121936 for details.

(cherry picked from commit bf537ce68dee63d81957c87b81c78c2b32d223de)