cairo: Don't disable the deprecation warnings during compilation

This makes the "#pragma warning disable 612" in Pattern.cs that were
removed previously actually useful, so we add it back.

cairo/Makefile.am

@@ -70,7 +70,7 @@ build_sources = $(addprefix $(srcdir)/, $(sources)) $(builddir)/AssemblyInfo.cs
 
 $(ASSEMBLY): $(build_sources) $(SNK)
 	@rm -f $(ASSEMBLY).mdb
-	$(CSC) $(CSFLAGS) -keyfile:$(SNK) -nowarn:0169,0612,0618 -out:$(ASSEMBLY) -target:library $(references) $(build_sources)
+	$(CSC) $(CSFLAGS) -keyfile:$(SNK) -out:$(ASSEMBLY) -target:library $(references) $(build_sources)
 
 install-data-local:
 	@if test -n '$(TARGET)'; then							\

cairo/Pattern.cs

@@ -135,10 +135,12 @@ namespace Cairo {
 			}
 		}
 
+#pragma warning disable 612
 		public IntPtr Handle {
 			get { return pattern; }
 			private set { pattern = value; }
 		}
+#pragma warning restore 612
 
 		[Obsolete]
 		public IntPtr Pointer {