Check for shared lib support before running ld tests with -shared

Another fix now that we run these tests non-native.

	* testsuite/ld-elf/audit.exp: Check for shared lib support.
	* testsuite/ld-elf/compress.exp: Likewise.
	* testsuite/ld-elf/dwarf.exp: Likewise.
	* testsuite/ld-elf/shared.exp: Likewise.
	* testsuite/ld-elf/wrap.exp: Likewise.
	* testsuite/ld-ifunc/ifunc.exp: Likewise.
	* testsuite/ld-plugin/lto.exp: Check $CXX exists.

ld/ChangeLog

@@ -1,3 +1,13 @@
+2017-01-04  Alan Modra  <amodra@gmail.com>
+
+	* testsuite/ld-elf/audit.exp: Check for shared lib support.
+	* testsuite/ld-elf/compress.exp: Likewise.
+	* testsuite/ld-elf/dwarf.exp: Likewise.
+	* testsuite/ld-elf/shared.exp: Likewise.
+	* testsuite/ld-elf/wrap.exp: Likewise.
+	* testsuite/ld-ifunc/ifunc.exp: Likewise.
+	* testsuite/ld-plugin/lto.exp: Check $CXX exists.
+
 2017-01-03  Alan Modra  <amodra@gmail.com>
 
 	* testsuite/lib/ld-lib.exp (run_ld_link_exec_tests): Do not

ld/testsuite/ld-elf/audit.exp

@@ -25,6 +25,12 @@ if ![is_elf_format] {
     return
 }
 
+# Skip targets where -shared is not supported
+
+if ![check_shared_lib_support] {
+    return
+}
+
 # Check if compiler works
 if { [which $CC] == 0 } {
     return

ld/testsuite/ld-elf/compress.exp

@@ -25,6 +25,12 @@ if ![is_elf_format] {
     return
 }
 
+# Skip targets where -shared is not supported
+
+if ![check_shared_lib_support] {
+    return
+}
+
 # Check if compiler works
 if { [which $CC] == 0 } {
     return

ld/testsuite/ld-elf/dwarf.exp

@@ -29,6 +29,12 @@ if ![is_elf_format] {
     return
 }
 
+# Skip targets where -shared is not supported
+
+if ![check_shared_lib_support] {
+    return
+}
+
 # Check if compiler works
 if { [which $CC] == 0 } {
     return

ld/testsuite/ld-elf/shared.exp

@@ -25,6 +25,12 @@ if ![is_elf_format] {
     return
 }
 
+# Skip targets where -shared is not supported
+
+if ![check_shared_lib_support] {
+    return
+}
+
 # Check to see if the C compiler works
 if { [which $CC] == 0 } {
     return

ld/testsuite/ld-elf/wrap.exp

@@ -25,6 +25,12 @@ if ![is_elf_format] {
     return
 }
 
+# Skip targets where -shared is not supported
+
+if ![check_shared_lib_support] {
+    return
+}
+
 # Check if compiler works
 if { [which $CC] == 0 } {
     return

ld/testsuite/ld-ifunc/ifunc.exp

@@ -41,6 +41,12 @@ if {!(([istarget "i?86-*-*"]
     return
 }
 
+# Skip targets where -shared is not supported
+
+if ![check_shared_lib_support] {
+    return
+}
+
 # We need a working compiler.  (Strictly speaking this is
 # not true, we could use target specific assembler files).
 if { [which $CC] == 0 } {

ld/testsuite/ld-plugin/lto.exp

@@ -18,8 +18,8 @@
 # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
 # MA 02110-1301, USA.
 
-# Check to see if the C compiler works
-if { [which $CC] == 0 } {
+# Check to see if the C and C++ compilers work
+if { [which $CC] == 0 || [which $CXX] == 0 } {
     return
 }