[JITLink] Use Blocks rather than Symbols for SectionRange.

This ensures that anonymous blocks are included in the section range.

Author: lhames

llvm/include/llvm/ExecutionEngine/JITLink/JITLink.h

@@ -615,21 +615,21 @@ class SectionRange {
 public:
   SectionRange() = default;
   SectionRange(const Section &Sec) {
-    if (llvm::empty(Sec.symbols()))
+    if (llvm::empty(Sec.blocks()))
       return;
-    First = Last = *Sec.symbols().begin();
-    for (auto *Sym : Sec.symbols()) {
-      if (Sym->getAddress() < First->getAddress())
-        First = Sym;
-      if (Sym->getAddress() > Last->getAddress())
-        Last = Sym;
+    First = Last = *Sec.blocks().begin();
+    for (auto *B : Sec.blocks()) {
+      if (B->getAddress() < First->getAddress())
+        First = B;
+      if (B->getAddress() > Last->getAddress())
+        Last = B;
     }
   }
-  Symbol *getFirstSymbol() const {
+  Block *getFirstBlock() const {
     assert((!Last || First) && "First can not be null if end is non-null");
     return First;
   }
-  Symbol *getLastSymbol() const {
+  Block *getLastBlock() const {
     assert((First || !Last) && "Last can not be null if start is non-null");
     return Last;
   }
@@ -638,17 +638,16 @@ class SectionRange {
     return !First;
   }
   JITTargetAddress getStart() const {
-    return First ? First->getBlock().getAddress() : 0;
+    return First ? First->getAddress() : 0;
   }
   JITTargetAddress getEnd() const {
-    return Last ? Last->getBlock().getAddress() + Last->getBlock().getSize()
-                : 0;
+    return Last ? Last->getAddress() + Last->getSize() : 0;
   }
   uint64_t getSize() const { return getEnd() - getStart(); }
 
 private:
-  Symbol *First = nullptr;
-  Symbol *Last = nullptr;
+  Block *First = nullptr;
+  Block *Last = nullptr;
 };
 
 class LinkGraph {