Add intrinsics.type_enum_is_contiguous test

tests/internal/test_intrinsics_enum_contiguous.odin

@@ -0,0 +1,24 @@
+package test_internal
+
+import "base:intrinsics"
+import "core:testing"
+
+@(test)
+test_intrinsics_enum_is_contiguous :: proc(t: ^testing.T) {
+	contiguous :: intrinsics.type_enum_is_contiguous
+	testing.expect(t, contiguous(enum { A=0, B=0, C=0 }))
+	testing.expect(t, contiguous(enum { A=0, B=1, C=2 }))
+	testing.expect(t, contiguous(enum { A=1, B=2, C=2 }))
+	testing.expect(t, contiguous(enum { A=-2, B=-1, C=0 }))
+	testing.expect(t, contiguous(enum { A=-8, B=-6, C=-7, D=-8 }))
+	testing.expect(t, contiguous(enum { C=4, A=3 }))
+	testing.expect(t, contiguous(enum { }))
+	testing.expect(t, contiguous(enum { A }))
+	testing.expect(t, contiguous(enum { Delta=-4 }))
+	testing.expect(t, contiguous(enum { X = 2 * len([?]u8{ 0 }) }))
+	testing.expect(t, contiguous(enum { Alpha=-2, Beta=-1, Gamma=0, Delta=-3 }))
+	
+	testing.expect(t, !contiguous(enum { A=1, B=3 }))
+	testing.expect(t, !contiguous(enum { B=-5, Beta=-3 }))
+	testing.expect(t, !contiguous(enum { A=0, B=-2 }))
+}