Declare AR and RANLIB as scons options so the ebuild can pass the
toolchain's own binaries. Godot's SConstruct declares CC and CXX but
neither of these, so without this scons silently uses its own defaults
and a cross or non-default toolchain is ignored. Gentoo bug #977691
covers AR; RANLIB has the same problem and is fixed here alongside.

NOTE the mechanism differs from ::gentoo's patch of the same purpose,
which is why this file no longer shares its name. ::gentoo exports the
variables (tc-export) and patches platform/linuxbsd/detect.py to read
os.environ; this passes them as scons command-line variables, which is
what dev-games/godot's src_compile here already does for CC and CXX.
Neither is more correct; mixing them is what breaks.
--- a/SConstruct
+++ b/SConstruct
@@ -304,2 +304,4 @@
 opts.Add("CC", "C compiler binary")
+opts.Add("AR", "Archiver")
+opts.Add("RANLIB", "Ranlib")
 opts.Add("LINK", "Linker binary")
@@ -745,3 +746,3 @@
         # `-msse2` is implied when compiling for x86_64.
-        env.Append(CCFLAGS=["-msse4.2", "-mpopcnt"])
+        pass
 elif env["arch"] == "x86_32":
@@ -817,3 +818,3 @@
         else:
-            env.AppendUnique(LINKFLAGS=["-s"])
+            pass