stdenv: make -nostdinc work as intended

Right now we add glibc to search path also -nostdinc was provided,
which breaks projects providing their own gcc.

pkgs/test/cc-wrapper/default.nix

@@ -45,6 +45,14 @@ in stdenv.mkDerivation {
     NIX_LDFLAGS="-L$NIX_BUILD_TOP/foo/lib -rpath $NIX_BUILD_TOP/foo/lib" $CC -lfoo -o ldflags-check ${./ldflags-main.c}
     ./ldflags-check
 
+    printf "Check whether -nostdinc and -nostdinc++ is handled correctly" >&2
+    mkdir -p std-include
+    cp ${./stdio.h} std-include/stdio.h
+    NIX_DEBUG=1 $CC -I std-include -nostdinc -o nostdinc-main ${./nostdinc-main.c}
+    ./nostdinc-main
+    $CXX -I std-include -nostdinc++ -o nostdinc-main++ ${./nostdinc-main.c}
+    ./nostdinc-main++
+
     ${optionalString sanitizersWorking ''
       printf "checking whether sanitizers are fully functional... ">&2
       $CC -o sanitizers -fsanitize=address,undefined ${./sanitizers.c}

pkgs/test/cc-wrapper/nostdinc-main.c

@@ -0,0 +1,8 @@
+// This one should not come from libc because of -nostdinc
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+  // provided by our own stdio.h
+  foo();
+  return 0;
+}

pkgs/test/cc-wrapper/stdio.h

@@ -0,0 +1 @@
+static void foo(void) {}