unwind fix for musl

On behalf of szabolcs.nagy@arm.com

2015-04-22  Gregor Richards  <gregor.richards@uwaterloo.ca>
	    Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* unwind-dw2-fde-dip.c (USE_PT_GNU_EH_FRAME): Define it on
	Linux if target provides dl_iterate_phdr.

Co-Authored-By: Szabolcs Nagy <szabolcs.nagy@arm.com>

From-SVN: r222328

libgcc/ChangeLog

+2015-04-22  Gregor Richards  <gregor.richards@uwaterloo.ca>
+	    Szabolcs Nagy  <szabolcs.nagy@arm.com>
+
+	* unwind-dw2-fde-dip.c (USE_PT_GNU_EH_FRAME): Define it on
+	Linux if target provides dl_iterate_phdr.
+
 2015-04-17  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/65612

libgcc/unwind-dw2-fde-dip.c

@@ -59,6 +59,12 @@
 
 #if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
     && defined(TARGET_DL_ITERATE_PHDR) \
+    && defined(__linux__)
+# define USE_PT_GNU_EH_FRAME
+#endif
+
+#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
+    && defined(TARGET_DL_ITERATE_PHDR) \
     && (defined(__DragonFly__) || defined(__FreeBSD__))
 # define ElfW __ElfN
 # define USE_PT_GNU_EH_FRAME