Simplify EEFileLoadException: delegating ctor and throw site

- Make the diagnosticInfo constructor delegate to the base constructor
  instead of duplicating its body.
- Remove the unnecessary IsEmpty check at the throw site in
  AppDomain::BindAssemblySpec — always pass bindDiagnosticInfo since
  CreateThrowable already gates on m_diagnosticInfo.IsEmpty().

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: elinor-fung

src/coreclr/vm/appdomain.cpp

@@ -3193,11 +3193,7 @@ PEAssembly * AppDomain::BindAssemblySpec(
 
                         if (fFailure && fThrowOnFileNotFound)
                         {
-                            if (!bindDiagnosticInfo.IsEmpty())
-                            {
-                                EEFileLoadException::Throw(pFailedSpec, COR_E_FILENOTFOUND, bindDiagnosticInfo, NULL);
-                            }
-                            EEFileLoadException::Throw(pFailedSpec, COR_E_FILENOTFOUND, NULL);
+                            EEFileLoadException::Throw(pFailedSpec, COR_E_FILENOTFOUND, bindDiagnosticInfo, NULL);
                         }
                     }
                 }

src/coreclr/vm/clrex.cpp

@@ -1453,10 +1453,7 @@ EEFileLoadException::EEFileLoadException(const SString &name, HRESULT hr, Except
 
 
 EEFileLoadException::EEFileLoadException(const SString &name, HRESULT hr, const SString &diagnosticInfo, Exception *pInnerException/* = NULL*/)
-  : EEException(GetFileLoadKind(hr)),
-    m_name(name),
-    m_hr(hr),
-    m_diagnosticInfo(diagnosticInfo)
+  : EEFileLoadException(name, hr, pInnerException)
 {
     CONTRACTL
     {
@@ -1466,11 +1463,7 @@ EEFileLoadException::EEFileLoadException(const SString &name, HRESULT hr, const
     }
     CONTRACTL_END;
 
-    _ASSERTE(pInnerException == NULL || !(pInnerException->IsTransient()));
-    m_innerException = pInnerException ? pInnerException->DomainBoundClone() : NULL;
-
-    if (m_name.IsEmpty())
-        m_name.Set(W("<Unknown>"));
+    m_diagnosticInfo.Set(diagnosticInfo);
 }