libphobos, testsuite: Add prune clauses for two Darwin cases.

Depending on the permutation of CPU, OS version and shared/non-
shared library inclusion, we get can get two warnings from the
external tools (ld64, dsymutil) which are not actually GCC issues
but relate to the external tools.  These are alrrady pruned in
the main testsuite, this adds them to the library.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>

libphobos/ChangeLog:

	* testsuite/lib/libphobos.exp: Prune warnings from external
	tool bugs.

libphobos/testsuite/lib/libphobos.exp

@@ -90,6 +90,13 @@ proc libphobos-dg-test { prog do_what extra_tool_flags } {
 }
 
 proc libphobos-dg-prune { system text } {
+
+    # Ignore harmless warnings from Xcode.
+    regsub -all "(^|\n)\[^\n\]*ld: warning: could not create compact unwind for\[^\n\]*" $text "" text
+
+    # Ignore dsymutil warning (tool bug is actually linker)
+    regsub -all "(^|\n)\[^\n\]*could not find object file symbol for symbol\[^\n\]*" $text "" text
+
     return $text
 }