protect CFLAGS from being smashed by AC_PROG_CC
AC_PROG_CC_C99 calls AC_PROC_CC, which calls _AC_PROG_CC_G, which sets default CFLAGS, whose contents are not customisable. We don't welcome this behaviour.
The exact same thing happens for CXXFLAGS in AC_PROG_CXX.
Added by shyouhei (Shyouhei Urabe) almost 5 years ago
protect CFLAGS from being smashed by AC_PROG_CC
AC_PROG_CC_C99 calls AC_PROC_CC, which calls _AC_PROG_CC_G, which sets
default CFLAGS, whose contents are not customisable. We don't welcome
this behaviour.
The exact same thing happens for CXXFLAGS in AC_PROG_CXX.