Update to work with LLVM 2.7.

Removed use of dyn_cast, llvm no compiles
without exceptions and rtti by
default. We do need exceptions for the libconfig stuff, but rtti isn't
necessary (anymore).

Debug info needs to be rewritten, as in LLVM 2.7 the format has
completely changed. To have something to look at while rewriting, the
old code has been wrapped inside #ifndef DISABLE_DEBUG_INFO , this means
that you have to define this to compile at the moment.

Updated tango 0.99.9 patch to include updated EH runtime code, which is
needed for LLVM 2.7 as well.

dmd/expression.h

@@ -41,6 +41,7 @@ struct TemplateDeclaration;
 struct ClassDeclaration;
 struct HdrGenState;
 struct BinExp;
+struct AssignExp;
 struct InterState;
 struct OverloadSet;
 
@@ -177,6 +178,8 @@ struct Expression : Object
     virtual void cacheLvalue(IRState* irs);
 
     llvm::Value* cachedLvalue;
+
+    virtual AssignExp* isAssignExp() { return NULL; }
 #endif
 };
 
@@ -942,7 +945,7 @@ struct DotIdExp : UnaExp
 struct DotTemplateExp : UnaExp
 {
     TemplateDeclaration *td;
-    
+
     DotTemplateExp(Loc loc, Expression *e, TemplateDeclaration *td);
     void toCBuffer(OutBuffer *buf, HdrGenState *hgs);
 };
@@ -1378,6 +1381,8 @@ struct AssignExp : BinExp
 #if IN_LLVM
     DValue* toElem(IRState* irs);
 #endif
+
+    AssignExp* isAssignExp() { return this; }
 };
 
 #if IN_DMD

dmd/statement.h

@@ -141,6 +141,7 @@ struct Statement : Object
     virtual ReturnStatement *isReturnStatement() { return NULL; }
     virtual IfStatement *isIfStatement() { return NULL; }
     virtual CaseStatement* isCaseStatement() { return NULL; }
+    virtual LabelStatement* isLabelStatement() { return NULL; }
 
 #if IN_LLVM
     virtual void toNakedIR(IRState *irs);
@@ -492,7 +493,7 @@ struct SwitchStatement : Statement
     Array gotoCases;		// array of unresolved GotoCaseStatement's
     Array *cases;		// array of CaseStatement's
     int hasNoDefault;		// !=0 if no default statement
-    
+
     // LDC
     Statement *enclosingScopeExit;
 
@@ -536,7 +537,7 @@ struct CaseStatement : Statement
     void toIR(IRState *irs);
 
     CaseStatement* isCaseStatement() { return this; }
-    
+
     // LDC
     llvm::BasicBlock* bodyBB;
     llvm::ConstantInt* llvmIdx;
@@ -863,6 +864,8 @@ struct LabelStatement : Statement
     // LDC
     bool asmLabel;       // for labels inside inline assembler
     void toNakedIR(IRState *irs);
+
+    LabelStatement* isLabelStatement() { return this; }
 };
 
 struct LabelDsymbol : Dsymbol