[llvm] [PPC] Don't emit overflow error on branches accross different sections. (PR #206812)

[Zarko Todorovski via llvm-commits]

================
@@ -553,6 +553,36 @@ static MCSectionXCOFF *getContainingCsect(const MCSymbolXCOFF *XSym) {
   return XSym->getRepresentedCsect();
 }
 
+// Checks that the section that contains the fragment F and the section
+// that contains the Target are different.
+static bool haveDifferentSections(const MCFragment &F, MCValue Target) {
+  const MCSymbol *TargetSym = Target.getAddSym();
+  if (!TargetSym)
+    return false;
+
+  // Target is externally defined.
+  if (!TargetSym->isDefined())
+    return true;
+
+  const MCSection *FragSection = F.getParent();
+  const MCSection *TargetSection = TargetSym->getFragment()->getParent();
+  return TargetSection != FragSection;
+}
+
+static bool callOverflows(MCFixupKindInfo Info, uint64_t FixedValue) {
+  if (Info.TargetSize != 24)
+    report_fatal_error("Unexepected call fixup kind for XCOFF");
+
+  return !isIntN(26, FixedValue);
+}
+
+static uint64_t normalizeCallOffset(MCFixupKindInfo Info, uint64_t Offset) {
+  if (Info.TargetSize != 24)
+    report_fatal_error("Unexepected call fixup kind for XCOFF");
----------------
ZarkoT wrote:

```suggestion
    report_fatal_error("Unexpected call fixup kind for XCOFF");
```

https://github.com/llvm/llvm-project/pull/206812