Add Platform methods for BSD distros

Author: tonchis

core/Platform.savi

@@ -34,6 +34,18 @@
   :: If true, it implies that `is_posix` is also true.
   :const is_bsd Bool: compiler intrinsic
 
+  :: Returns `True` if the target platform uses a FreeBSD operating system.
+  :const is_freebsd Bool: compiler intrinsic
+
+  :: Returns `True` if the target platform uses a OpenBSD operating system.
+  :const is_openbsd Bool: compiler intrinsic
+
+  :: Returns `True` if the target platform uses a NetBSD operating system.
+  :const is_netbsd Bool: compiler intrinsic
+
+  :: Returns `True` if the target platform uses a Dragonfly operating system.
+  :const is_dragonfly Bool: compiler intrinsic
+
   :: Returns `True` if the target platform uses a MacOS operating system.
   ::
   :: This is mutually exclusive with `is_linux`, `is_bsd`, and `is_windows`.

spec/core/Platform.Spec.savi

@@ -9,6 +9,14 @@
       if Platform.is_macos   (1 | 0) +
       if Platform.is_windows (1 | 0)
 
+  :it "detects FreeBSD, OpenBSD, NetBSD and Dragonfly"
+    if Platform.is_bsd (assert: (
+      Platform.is_freebsd ||
+      Platform.is_openbsd ||
+      Platform.is_netbsd  ||
+      Platform.is_dragonfly
+    ))
+
   :it "returns True for is_posix on POSIX platforms"
     if Platform.is_linux   (assert: Platform.is_posix)
     if Platform.is_bsd     (assert: Platform.is_posix)

src/savi/compiler/code_gen.cr

@@ -1003,6 +1003,14 @@ class Savi::Compiler::CodeGen
         gen_bool(target.linux?)
       when "is_bsd"
         gen_bool(target.bsd?)
+      when "is_freebsd"
+        gen_bool(target.freebsd?)
+      when "is_openbsd"
+        gen_bool(target.openbsd?)
+      when "is_netbsd"
+        gen_bool(target.netbsd?)
+      when "is_dragonfly"
+        gen_bool(target.dragonfly?)
       when "is_macos"
         gen_bool(target.macos?)
       when "is_posix"