Require GNAT debug info for some Ada tests

A few Ada tests require some debug info in the GNAT runtime.  When run
without this info, these tests can't pass.  This patch changes these
tests to detect this situation and stop with "untested".

gdb/testsuite/gdb.ada/interface.exp

@@ -17,6 +17,11 @@ load_lib "ada.exp"
 
 if { [skip_ada_tests] } { return -1 }
 
+if {![gnat_runtime_has_debug_info]} {
+    untested "GNAT runtime debuginfo required for this test"
+    return -1
+}
+
 standard_ada_testfile foo
 
 if {[gdb_compile_ada "${srcfile}" "${binfile}" executable [list debug additional_flags=-gnat05 ]] != "" } {

gdb/testsuite/gdb.ada/iwide.exp

@@ -17,6 +17,11 @@ load_lib "ada.exp"
 
 if { [skip_ada_tests] } { return -1 }
 
+if {![gnat_runtime_has_debug_info]} {
+    untested "GNAT runtime debuginfo required for this test"
+    return -1
+}
+
 standard_ada_testfile p
 
 if {[gdb_compile_ada "${srcfile}" "${binfile}" executable [list debug additional_flags=-gnat05 ]] != "" } {

gdb/testsuite/gdb.ada/mi_interface.exp

@@ -17,6 +17,11 @@ load_lib "ada.exp"
 
 if { [skip_ada_tests] } { return -1 }
 
+if {![gnat_runtime_has_debug_info]} {
+    untested "GNAT runtime debuginfo required for this test"
+    return -1
+}
+
 standard_ada_testfile foo
 
 if {[gdb_compile_ada "${srcfile}" "${binfile}" executable [list debug additional_flags=-gnat12 ]] != "" } {

gdb/testsuite/gdb.ada/tagged.exp

@@ -17,6 +17,11 @@ load_lib "ada.exp"
 
 if { [skip_ada_tests] } { return -1 }
 
+if {![gnat_runtime_has_debug_info]} {
+    untested "GNAT runtime debuginfo required for this test"
+    return -1
+}
+
 standard_ada_testfile foo
 
 if {[gdb_compile_ada "${srcfile}" "${binfile}" executable [list debug]] != "" } {

gdb/testsuite/gdb.ada/tagged_access.exp

@@ -17,6 +17,11 @@ load_lib "ada.exp"
 
 if { [skip_ada_tests] } { return -1 }
 
+if {![gnat_runtime_has_debug_info]} {
+    untested "GNAT runtime debuginfo required for this test"
+    return -1
+}
+
 standard_ada_testfile p
 
 if {[gdb_compile_ada "${srcfile}" "${binfile}" executable [list debug]] != "" } {