Update LLVM and add Unsupported diagnostic

Secure entry functions do not support if arguments are passed on the
stack. An "unsupported" diagnostic will be emitted by LLVM if that is
the case.
This commits adds support in Rust for that diagnostic so that an error
will be output if that is the case!

Signed-off-by: Hugues de Valon <hugues.devalon@arm.com>

compiler/rustc_codegen_llvm/src/llvm/diagnostic.rs

@@ -118,6 +118,7 @@ pub enum Diagnostic<'ll> {
     InlineAsm(InlineAsmDiagnostic<'ll>),
     PGO(&'ll DiagnosticInfo),
     Linker(&'ll DiagnosticInfo),
+    Unsupported(&'ll DiagnosticInfo),
 
     /// LLVM has other types that we do not wrap here.
     UnknownDiagnostic(&'ll DiagnosticInfo),
@@ -159,6 +160,7 @@ impl Diagnostic<'ll> {
 
             Dk::PGOProfile => PGO(di),
             Dk::Linker => Linker(di),
+            Dk::Unsupported => Unsupported(di),
 
             _ => UnknownDiagnostic(di),
         }