Don't use an executable stack. Bug 283709 r/sr=shaver/brendan a=dbaron

xpcom/reflect/xptcall/src/md/unix/xptcinvoke_asm_ipf64.s

@@ -142,4 +142,5 @@ XPTC_InvokeByIndex::
 
         .endp
 
-
+/* Magic indicating no need for an executable stack */
+.section .note.GNU-stack, "", @progbits ; .previous

xpcom/reflect/xptcall/src/md/unix/xptcinvoke_asm_ppc_linux.s

@@ -111,3 +111,6 @@ XPTC_InvokeByIndex:
 	mtlr    r0
 	mr      sp,r11
 	blr
+
+/* Magic indicating no need for an executable stack */
+.section .note.GNU-stack, "", @progbits ; .previous

xpcom/reflect/xptcall/src/md/unix/xptcstubs_asm_ipf64.s

@@ -121,4 +121,5 @@ SharedStub::
 
         .endp
 
-
+/* Magic indicating no need for an executable stack */
+.section .note.GNU-stack, "", @progbits ; .previous

xpcom/reflect/xptcall/src/md/unix/xptcstubs_asm_ppc_linux.s

@@ -87,3 +87,5 @@ SharedStub:
 	la	sp,112(sp)			// clean up the stack
 	blr
 
+/* Magic indicating no need for an executable stack */
+.section .note.GNU-stack, "", @progbits ; .previous