libctf: tests: prune warnings from compiler output

We were failing to call prune_warnings appropriately, leading to
false-positive test failures on some platforms (observed on
sparclinux).

libctf/ChangeLog:

	* testsuite/lib/ctf-lib.exp: Prune warnings from compiler and
	linker output.
	* testsuite/libctf-regression/libctf-repeat-cu.exp: Likewise,
	and ar output too.

libctf/testsuite/lib/ctf-lib.exp

@@ -181,7 +181,7 @@ proc run_lookup_test { name } {
     }
 
     # Compile and link the lookup program.
-    set comp_output [compile_link_one_host_cc $opts(lookup) "tmpdir/lookup" "libctf.la"]
+    set comp_output [prune_warnings [compile_link_one_host_cc $opts(lookup) "tmpdir/lookup" "libctf.la"]]
 
     if { $comp_output != ""} {
 	send_log "compilation of lookup program $opts(lookup) failed with <$comp_output>"
@@ -217,7 +217,7 @@ proc run_lookup_test { name } {
 	    }
 	}
 
-	set comp_output [run_host_cmd "$CC_FOR_TARGET" "$CFLAGS_FOR_TARGET $lookup_flags [concat $src] -o $lookup_output"]
+	set comp_output [prune_warnings [run_host_cmd "$CC_FOR_TARGET" "$CFLAGS_FOR_TARGET $lookup_flags [concat $src] -o $lookup_output"]]
 
 	if { $comp_output != ""} {
 	    send_log "compilation of CTF program [concat $src] failed with <$comp_output>"

libctf/testsuite/libctf-regression/libctf-repeat-cu.exp

@@ -52,12 +52,12 @@ proc one_lib_compile { src flags obj archive } {
 	set src [file join $subsrcdir $src]
     }
 
-    set comp_output [run_host_cmd "$CC_FOR_TARGET" "$CFLAGS_FOR_TARGET $flags -gctf -fPIC -c -o $obj $src"]
+    set comp_output [prune_warnings [run_host_cmd "$CC_FOR_TARGET" "$CFLAGS_FOR_TARGET $flags -gctf -fPIC -c -o $obj $src"]]
     if { $comp_output != "" } {
 	return $comp_output
     }
 
-    set ar_output [run_host_cmd "$AR" "rc $archive $obj"]
+    set ar_output [prune_warnings [run_host_cmd "$AR" "rc $archive $obj"]]
     return $comp_output
 }
 
@@ -94,7 +94,7 @@ if [is_remote host] {
     set src [file join $subsrcdir libctf-repeat-cu-main.c]
 }
 
-set comp_output [run_host_cmd "$CC_FOR_TARGET" "$CFLAGS_FOR_TARGET -gctf -fPIC -shared -o tmpdir/libctf-repeat-cu-main.so $src tmpdir/a.a tmpdir/b.a tmpdir/c.a"]
+set comp_output [prune_warnings [run_host_cmd "$CC_FOR_TARGET" "$CFLAGS_FOR_TARGET -gctf -fPIC -shared -o tmpdir/libctf-repeat-cu-main.so $src tmpdir/a.a tmpdir/b.a tmpdir/c.a"]]
 if { $comp_output != "" } {
     send_log "compilation of tmpdir/libctf-repeat-cu-main.so failed"
     perror "compilation of tmpdir/libctf-repeat-cu-main.so failed"
@@ -102,7 +102,7 @@ if { $comp_output != "" } {
     return $comp_output
 }
 
-set comp_output [run_host_cmd "$OBJDUMP" "--ctf tmpdir/libctf-repeat-cu-main.so > tmpdir/dump.out"]
+set comp_output [prune_warnings [run_host_cmd "$OBJDUMP" "--ctf tmpdir/libctf-repeat-cu-main.so > tmpdir/dump.out"]]
 
 if { [regexp_diff "tmpdir/dump.out"  [file join $subsrcdir libctf-repeat-cu.d] ] } {
     fail $testname