change EH related stuff (other than EH_LABEL) to use MCSymbol

instead of label ID's.  This cleans up and regularizes a bunch 
of code and makes way for future progress.

Unfortunately, this pointed out to me that JITDwarfEmitter.cpp
is largely copy and paste from DwarfException/MachineModuleInfo
and other places.  This is very sad and disturbing. :(

One major change here is that TidyLandingPads moved from being
called in DwarfException::BeginFunction to being called in
DwarfException::EndFunction.  There should not be any 
functionality change from doing this, but I'm not an EH expert.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98459 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachineCodeEmitter.h

@@ -31,6 +31,7 @@ class MachineRelocation;
 class Value;
 class GlobalValue;
 class Function;
+class MCSymbol;
 
 /// MachineCodeEmitter - This class defines two sorts of methods: those for
 /// emitting the actual bytes of machine code, and those for emitting auxillary
@@ -247,7 +248,7 @@ public:
   virtual void processDebugLoc(DebugLoc DL, bool BeforePrintintInsn) {}
 
   /// emitLabel - Emits a label
-  virtual void emitLabel(uint64_t LabelID) = 0;
+  virtual void emitLabel(MCSymbol *Label) = 0;
 
   /// allocateSpace - Allocate a block of space in the current output buffer,
   /// returning null (and setting conditions to indicate buffer overflow) on
@@ -316,10 +317,10 @@ public:
   ///
   virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const= 0;
 
-  /// getLabelAddress - Return the address of the specified LabelID, only usable
+  /// getLabelAddress - Return the address of the specified Label, only usable
   /// after the LabelID has been emitted.
   ///
-  virtual uintptr_t getLabelAddress(uint64_t LabelID) const = 0;
+  virtual uintptr_t getLabelAddress(MCSymbol *Label) const = 0;
   
   /// Specifies the MachineModuleInfo object. This is used for exception handling
   /// purposes.