[BitCode] decode nossp fn attr

[nickdesaulniers]

Summary

I missed this in https://reviews.llvm.org/D87956.

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

static Attribute::AttrKind getAttrFromCode(uint64_t Code) {
   case bitc::ATTR_KIND_PREALLOCATED:
     return Attribute::Preallocated;
   case bitc::ATTR_KIND_NOUNDEF:
     return Attribute::NoUndef;
   case bitc::ATTR_KIND_BYREF:
     return Attribute::ByRef;
   case bitc::ATTR_KIND_MUSTPROGRESS:
     return Attribute::MustProgress;
+  case bitc::ATTR_KIND_NO_STACK_PROTECT:
+    return Attribute::NoStackProtect;
   }
 }
 
 Error BitcodeReader::parseAlignmentValue(uint64_t Exponent,
                                          MaybeAlign &Alignment) {
   // Note: Alignment in bitcode files is incremented by 1, so that zero
   // can be used for default alignment.
   if (Exponent > Value::MaxAlignmentExponent + 1)

llvm/test/Bitcode/attributes.ll

 }
 
 ; CHECK: define void @f68() #41
 define void @f68() mustprogress
 {
   ret void
 }
 
+; CHECK; define void @f69() #42
+define void @f69() nossp
+{
+  ret void
+}
+
 ; CHECK: attributes #0 = { noreturn }
 ; CHECK: attributes #1 = { nounwind }
 ; CHECK: attributes #2 = { readnone }
 ; CHECK: attributes #3 = { readonly }
 ; CHECK: attributes #4 = { noinline }
 ; CHECK: attributes #5 = { alwaysinline }
 ; CHECK: attributes #6 = { optsize }
 ; CHECK: attributes #7 = { ssp }

 ; CHECK: attributes #34 = { sanitize_hwaddress }
 ; CHECK: attributes #35 = { shadowcallstack }
 ; CHECK: attributes #36 = { willreturn }
 ; CHECK: attributes #37 = { nofree }
 ; CHECK: attributes #38 = { nosync }
 ; CHECK: attributes #39 = { sanitize_memtag }
 ; CHECK: attributes #40 = { null_pointer_is_valid }
 ; CHECK: attributes #41 = { mustprogress }
+; CHECK: attributes #42 = { nossp }
 ; CHECK: attributes #[[NOBUILTIN]] = { nobuiltin }