ci: test -os linux cross compilation on macOS

.github/workflows/macos_ci.yml

@@ -98,3 +98,7 @@ jobs:
         run: v test examples/readline/
       - name: Test vlib modules with -skip-unused
         run: v -skip-unused test vlib/builtin/ vlib/math vlib/flag/ vlib/os/ vlib/strconv/
+      - name: Test cross compilation to Linux
+        run: |
+          v -d use_openssl -cc clang -showcc -gc none -o hi -os linux examples/hello_world.v
+          v -d use_openssl -cc clang -showcc -gc none -o hi -os linux examples/veb/veb_example.v

ROADMAP.md

@@ -43,13 +43,14 @@ For a list of all features and fixes, check out the changelog.
 - [x] Lambdas: `a.sort(|a, b| a > b)`
 - [ ] Custom attributes
 - [ ] Contexts that are passed implicitly (e.g. for custom allocation/memory management)
+- [ ] Direct C/C++ interop without generating wrappers
 
 ## [Version 0.6]
 
 - [ ] Integrate the new parallel parser/checker/cgen
 - [ ] Incremental compilation
+- [ ] Runtime race detector
 - [ ] [Thread safe maps](https://github.com/vlang/v/discussions/11729)
-- [ ] Direct C/C++ interop without generating wrappers
 - [ ] `recover()` from panics
 - [ ] -usecache on by default
 - [ ] -skip-unused on by default

vlib/picoev/loop_linux.c.v

@@ -1,6 +1,7 @@
 module picoev
 
 #include <sys/epoll.h>
+#include <sys/cdefs.h> // needed for cross compiling to linux
 
 fn C.epoll_create(int) int
 fn C.epoll_wait(int, voidptr, int, int) int

vlib/v/builder/cc.v

@@ -848,7 +848,7 @@ fn (mut b Builder) cc_linux_cross() {
 	obj_file := b.out_name_c + '.o'
 	cflags := b.get_os_cflags()
 	defines, others, libs := cflags.defines_others_libs()
-	mut cc_args := []string{}
+	mut cc_args := []string{cap: 20}
 	cc_args << '-w'
 	cc_args << '-fPIC'
 	cc_args << '-c'
@@ -916,7 +916,7 @@ fn (mut b Builder) cc_freebsd_cross() {
 	obj_file := b.out_name_c + '.o'
 	cflags := b.get_os_cflags()
 	defines, others, libs := cflags.defines_others_libs()
-	mut cc_args := []string{}
+	mut cc_args := []string{cap: 20}
 	cc_args << '-w'
 	cc_args << '-fPIC'
 	cc_args << '-c'