From c9731d6d (Synchronize bindist configure for #24324)

Autoconf can append a language-standard option to CC/CXX. Keep that option in
CFLAGS/CXXFLAGS so the installed compiler settings contain executable names.

https://gitlab.haskell.org/ghc/ghc/-/commit/c9731d6d

--- a/distrib/configure.ac.in
+++ b/distrib/configure.ac.in
@@ -109,6 +109,9 @@ dnl ** Which gcc to use?
 dnl --------------------------------------------------------------
 AC_PROG_CC([gcc clang])
 AC_PROG_CXX([g++ clang++ c++])
+# Work around #24324
+MOVE_TO_FLAGS([CC],[CFLAGS])
+MOVE_TO_FLAGS([CXX],[CXXFLAGS])
 
 dnl ** figure out how to invoke the C preprocessor (i.e. `gcc -E`)
 AC_PROG_CPP