[libc++abi][test][VE] Add UNSUPPORTED to pass tests on VE

Add UNSUPPORTED to pass tests on VE.  VE uses SjLj libunwind, so
_Unwind_Backtrace and _Unwind_ForcedUnwind are not implemented.

Reviewed By: MaskRay, #libc_abi, ldionne

Differential Revision: https://reviews.llvm.org/D159446

libcxxabi/test/backtrace_test.pass.cpp

@@ -8,6 +8,9 @@
 
 // UNSUPPORTED: no-exceptions
 
+// VE only supports SjLj and doesn't provide _Unwind_Backtrace.
+// UNSUPPORTED: target={{ve-.*}}
+
 #include <assert.h>
 #include <stddef.h>
 #include <unwind.h>

libcxxabi/test/forced_unwind1.pass.cpp

@@ -11,6 +11,9 @@
 
 // UNSUPPORTED: no-exceptions, c++03
 
+// VE only supports SjLj and doesn't provide _Unwind_ForcedUnwind.
+// UNSUPPORTED: target={{ve-.*}}
+
 // These tests fail on previously released dylibs, investigation needed.
 // XFAIL: stdlib=apple-libc++ && target={{.+}}-apple-macosx10.{{9|10|11|12|13|14|15}}
 // XFAIL: stdlib=apple-libc++ && target={{.+}}-apple-macosx{{11.0|12.0}}

libcxxabi/test/forced_unwind2.pass.cpp

@@ -10,6 +10,9 @@
 
 // UNSUPPORTED: no-exceptions, c++03
 
+// VE only supports SjLj and doesn't provide _Unwind_ForcedUnwind.
+// UNSUPPORTED: target={{ve-.*}}
+
 // These tests fail on previously released dylibs, investigation needed.
 // XFAIL: stdlib=apple-libc++ && target={{.+}}-apple-macosx10.{{9|10|11|12|13|14|15}}
 // XFAIL: stdlib=apple-libc++ && target={{.+}}-apple-macosx{{11.0|12.0}}

libcxxabi/test/forced_unwind3.pass.cpp

@@ -13,6 +13,9 @@
 // UNSUPPORTED: no-threads
 // UNSUPPORTED: no-exceptions
 
+// VE only supports SjLj and doesn't provide _Unwind_ForcedUnwind.
+// UNSUPPORTED: target={{ve-.*}}
+
 #include <assert.h>
 #include <exception>
 #include <stdlib.h>