ccache.c:738:18: runtime error: null pointer passed as argument 1, which is declared to never be null
Fixes stderr redirect in testname CCACHE_CPP2, when the CCACHE_CPP2
environment variable is defined.
mdfour.c:91:20: runtime error: left shift of 139 by 24 places cannot be represented in type 'int'
Looks like this brings some stability to the md4 hash calculation.
Closes#2449