Darwin/i386 NCG: fix assembly syntax in symbol stubs

In i386 position-independent symbol stubs, the NCG used to print
	jmp %edx
instead of
	jmp *%edx

Apple's assembler used to silently accept this, but has recently started to print warnings about it.

MERGE TO STABLE.

compiler/nativeGen/PositionIndependentCode.hs

@@ -442,7 +442,7 @@ pprImportedSymbol importedLbl
                 ptext SLIT("1:"),
                     ptext SLIT("\tmovl L") <> pprCLabel_asm lbl
                         <> ptext SLIT("$lazy_ptr-1b(%eax),%edx"),
-                    ptext SLIT("\tjmp %edx"),
+                    ptext SLIT("\tjmp *%edx"),
                 ptext SLIT("L") <> pprCLabel_asm lbl
                     <> ptext SLIT("$stub_binder:"),
                     ptext SLIT("\tlea L") <> pprCLabel_asm lbl