ld: Skip some x86 ifunc tests for lynxos and nto

On lynxos and nto:

regexp_diff match failure
regexp "^Relocation section '.rel(a|).plt' at offset 0x[0-9a-f]+ contains 1 entry:$"
line   "Relocation section '.rel.dyn' at offset 0x74 contains 1 entry:"
FAIL: ld-ifunc/ifunc-23a-x86

	* testsuite/ld-ifunc/ifunc-23a-x86.d: Skip *-*-lynxos *-*-nto*.
	* testsuite/ld-ifunc/ifunc-24a-x86.d: Likewise.
	* testsuite/ld-ifunc/ifunc-25a-x86.d: Likewise.

ld/ChangeLog

@@ -1,3 +1,9 @@
+2020-05-26  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* testsuite/ld-ifunc/ifunc-23a-x86.d: Skip *-*-lynxos *-*-nto*.
+	* testsuite/ld-ifunc/ifunc-24a-x86.d: Likewise.
+	* testsuite/ld-ifunc/ifunc-25a-x86.d: Likewise.
+
 2020-05-25  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* testsuite/ld-x86-64/x86-64.exp: Pass -z notext to linker.

ld/testsuite/ld-ifunc/ifunc-23a-x86.d

@@ -2,6 +2,7 @@
 #ld:
 #readelf: -r --wide
 #target: x86_64-*-* i?86-*-*
+#notarget: *-*-lynxos *-*-nto*
 
 Relocation section '.rel(a|).plt' at offset 0x[0-9a-f]+ contains 1 entry:
  +Offset +Info +Type +Sym.* Value +Symbol's Name.*

ld/testsuite/ld-ifunc/ifunc-24a-x86.d

@@ -2,6 +2,7 @@
 #ld:
 #readelf: -r --wide
 #target: x86_64-*-* i?86-*-*
+#notarget: *-*-lynxos *-*-nto*
 
 Relocation section '.rel(a|).plt' at offset 0x[0-9a-f]+ contains 1 entry:
  +Offset +Info +Type +Sym.* Value +Symbol's Name.*

ld/testsuite/ld-ifunc/ifunc-25a-x86.d

@@ -2,6 +2,7 @@
 #ld:
 #readelf: -r --wide
 #target: x86_64-*-* i?86-*-*
+#notarget: *-*-lynxos *-*-nto*
 
 Relocation section '.rel(a|).plt' at offset 0x[0-9a-f]+ contains 1 entry:
  +Offset +Info +Type +Sym.* Value +Symbol's Name.*