Remove unnecessary demangling operation (NFC)

This extra call to the demangler doesn't affect the performance of C++
because the result is being cached anyway; but I'm working on a patch
to the Swift branch that uses extra contextual information to provide
a more accurate demangling result. In that case this call would be
extra and unnecessary work.

Differential Revision: https://reviews.llvm.org/D58720

llvm-svn: 355042
diff --git a/lldb/source/Core/Mangled.cpp b/lldb/source/Core/Mangled.cpp
index f366ad6..5ab3fdf 100644
--- a/lldb/source/Core/Mangled.cpp
+++ b/lldb/source/Core/Mangled.cpp
@@ -490,13 +490,11 @@
 lldb::LanguageType Mangled::GuessLanguage() const {
   ConstString mangled = GetMangledName();
   if (mangled) {
-    if (GetDemangledName(lldb::eLanguageTypeUnknown)) {
-      const char *mangled_name = mangled.GetCString();
-      if (CPlusPlusLanguage::IsCPPMangledName(mangled_name))
-        return lldb::eLanguageTypeC_plus_plus;
-      else if (ObjCLanguage::IsPossibleObjCMethodName(mangled_name))
-        return lldb::eLanguageTypeObjC;
-    }
+    const char *mangled_name = mangled.GetCString();
+    if (CPlusPlusLanguage::IsCPPMangledName(mangled_name))
+      return lldb::eLanguageTypeC_plus_plus;
+    else if (ObjCLanguage::IsPossibleObjCMethodName(mangled_name))
+      return lldb::eLanguageTypeObjC;
   } else {
     // ObjC names aren't really mangled, so they won't necessarily be in the
     // mangled name slot.