Revert "[DWARF] Create subprogram's DIE in DISubprogram's unit"

This reverts commit ef0dcb5.

This change is causing a lot of compiler crashes inside, sorry I don't have a
small repro/stacktrace with symbols to share right now.

Differential Revision: https://reviews.llvm.org/D95622

Author: sureyeaah

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h

@@ -466,6 +466,9 @@ class DwarfDebug : public DebugHandlerBase {
   /// Construct a DIE for this abstract scope.
   void constructAbstractSubprogramScopeDIE(DwarfCompileUnit &SrcCU, LexicalScope *Scope);
 
+  /// Construct a DIE for the subprogram definition \p SP and return it.
+  DIE &constructSubprogramDefinitionDIE(const DISubprogram *SP);
+
   /// Construct DIEs for call site entries describing the calls in \p MF.
   void constructCallSiteEntryDIEs(const DISubprogram &SP, DwarfCompileUnit &CU,
                                   DIE &ScopeDIE, const MachineFunction &MF);
@@ -763,9 +766,6 @@ class DwarfDebug : public DebugHandlerBase {
   /// * DW_FORM_data4 for 32-bit DWARFv3 and DWARFv2.
   dwarf::Form getDwarfSectionOffsetForm() const;
 
-  /// Construct a DIE for the subprogram definition \p SP and return it.
-  DIE &constructSubprogramDefinitionDIE(const DISubprogram *SP);
-
   /// Returns the previous CU that was being updated
   const DwarfCompileUnit *getPrevCU() const { return PrevCU; }
   void setPrevCU(const DwarfCompileUnit *PrevCU) { this->PrevCU = PrevCU; }

llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp

@@ -545,13 +545,8 @@ DIE *DwarfUnit::getOrCreateContextDIE(const DIScope *Context) {
     return getOrCreateTypeDIE(T);
   if (auto *NS = dyn_cast<DINamespace>(Context))
     return getOrCreateNameSpace(NS);
-  if (auto *SP = dyn_cast<DISubprogram>(Context)) {
-    // Subprogram definitions should be created in the Unit that they specify,
-    // which might not be "this" unit when type definitions move around under
-    // LTO.
-    assert(SP->isDefinition());
-    return &DD->constructSubprogramDefinitionDIE(SP);
-  }
+  if (auto *SP = dyn_cast<DISubprogram>(Context))
+    return getOrCreateSubprogramDIE(SP);
   if (auto *M = dyn_cast<DIModule>(Context))
     return getOrCreateModule(M);
   return getDIE(Context);