ci: re-enable testing of `./v -freestanding run vlib/os/bare/bare_example_linux.v` on ubuntu

.github/workflows/ci.yml

@@ -358,8 +358,8 @@ jobs:
       #      run: git clone --depth 1 https://github.com/vlang/vorum && cd vorum && ../v . && cd ..
       #    - name: Build vpm
       #      run: git clone --depth 1 https://github.com/vlang/vpm && cd vpm && ../v . && cd ..
-      #    - name: Freestanding
-      #      run: ./v -freestanding -o bare vlib/os/bare/bare_example_linux.v
+      - name: Freestanding
+        run: ./v -freestanding run vlib/os/bare/bare_example_linux.v
       - name: v self compilation
         run: ./v -o v2 cmd/v && ./v2 -o v3 cmd/v && ./v3 -o v4 cmd/v
       - name: -usecache

vlib/builtin/linux_bare/linux_syscalls.v

@@ -236,7 +236,7 @@ fn sys_read(fd i64, buf &byte, count u64) (i64, Errno) {
 }
 
 // 1 sys_write
-fn sys_write(fd i64, buf &byte, count u64) (i64, Errno) {
+pub fn sys_write(fd i64, buf &byte, count u64) (i64, Errno) {
 	return split_int_errno(sys_call3(1, u64(fd), u64(buf), count))
 }
 

vlib/os/bare/bare_example_linux.v

@@ -4,4 +4,5 @@ fn main() {
 	sys_write(1, s.str, u64(s.len))
 	a := s[0]
 	println('Hello freestanding!')
+	println(a)
 }