Add a test for PR ld/22150

PR ld/22150
	* testsuite/ld-elf/pr22150.vd: New file.
	* testsuite/ld-elf/pr22150.ver: Likewise.
	* testsuite/ld-elf/pr22150a.s: Likewise.
	* testsuite/ld-elf/pr22150b.s: Likewise.
	* testsuite/ld-elf/shared.exp: Run PR ld/22150 tests.

ld/ChangeLog

@@ -1,3 +1,12 @@
+2017-09-22  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/22150
+	* testsuite/ld-elf/pr22150.vd: New file.
+	* testsuite/ld-elf/pr22150.ver: Likewise.
+	* testsuite/ld-elf/pr22150a.s: Likewise.
+	* testsuite/ld-elf/pr22150b.s: Likewise.
+	* testsuite/ld-elf/shared.exp: Run PR ld/22150 tests.
+
 2017-09-21  Alan Modra  <amodra@gmail.com>
 
 	* testsuite/ld-powerpc/tlsopt5.wf: Update for reduced alignment.

ld/testsuite/ld-elf/pr22150.vd

@@ -0,0 +1,2 @@
+
+No version information found in this file.

ld/testsuite/ld-elf/pr22150.ver

@@ -0,0 +1,6 @@
+BAR {
+global:
+	bar;
+local:
+	*;
+};

ld/testsuite/ld-elf/pr22150a.s

@@ -0,0 +1,6 @@
+	.text
+	.globl	bar
+	.type	bar, %function
+bar:
+	.byte 0
+	.size	bar, .-bar

ld/testsuite/ld-elf/pr22150b.s

@@ -0,0 +1,13 @@
+	.section .text._start,"ax",%progbits
+	.globl	_start
+	.type	_start, %function
+_start:
+	.byte 0
+	.size	_start, .-_start
+
+	.section .text.bar,"ax",%progbits
+	.globl	foo
+	.type	foo, %function
+foo:
+	.dc.a bar
+	.size	foo, .-foo

ld/testsuite/ld-elf/shared.exp

@@ -170,6 +170,29 @@ if { [check_gc_sections_available] } {
 	    "pr21233-3"]]
 }
 
+if { [check_gc_sections_available] } {
+    run_ld_link_tests [list \
+	[list \
+	    "Build pr22150.so" \
+	    "$LFLAGS -shared --version-script pr22150.ver" \
+	    "" \
+	    "$AFLAGS_PIC" \
+	    {pr22150a.s} \
+	    {} \
+	    "pr22150.so" \
+	] \
+	[list \
+	    "Build pr22150" \
+	    "$LFLAGS -e _start --gc-sections" \
+	    "tmpdir/pr22150.so" \
+	    "" \
+	    {pr22150b.s} \
+	    {{readelf -V pr22150.vd}} \
+	    "pr22150" \
+	] \
+    ]
+}
+
 # Check to see if the C compiler works
 if { [which $CC] == 0 } {
     return