Added compiled version of test.proto.

This avoids requiring protoc to be installed
just to build/run the basic tests.

When upb has its own .proto file parser we should
be able to remove this precompiled version from the
repository.

tests/test.proto.pb

@@ -0,0 +1,30 @@
+
+Þ
+tests/test.proto"
+
A
+
b
 
(2.B"!
+
B
+
b
 
(2.B
+
c 
(2.C"?
+
C
+
a
 
(2.A
+
b 
(2.B
+
d 
(2.D
+
e 
(2.E"0
+
D
+
a
 
(2.A
+
d 
(2.D
+
e 
(2.E"
+
E
+
e
 
(2.E"
+
F
+
e
 
(2.E"x
+SimplePrimitives
+u64
 
(
+u32 
(
+dbl 
(

+flt 
(
+i64 
(
+i32 
(	
+
b 
(
+str	 
(