[ELF][CHERI] Delete various unnecessary error messages and asserts

Some of these error messages should really have been asserts. Many of
these are now so clearly impossible due to the surrounding code that
they serve no point, and in general this is way more paranoid than LLD
typically is, in ways that make it harder to actually follow the code.
Delete this clutter.

Author: jrtc27

lld/ELF/Arch/Cheri.cpp

@@ -958,39 +958,12 @@ void addCapabilityRelocation(
     return;
   }
 
-  assert(sym && "ELF relocs should not be used against sections");
-  assert((sym->isPreemptible || needTrampoline) &&
-         "ELF relocs should not be used for non-preemptible symbols");
-  assert((!sym->isLocal() || needTrampoline) &&
-         "ELF relocs should not be used for local symbols");
-  if (!lld::elf::hasDynamicLinker(ctx)) {
-    error("attempting to emit a R_CAPABILITY relocation against " +
-          (sym->getName().empty() ? "local symbol"
-                                  : "symbol " + toStr(ctx, *sym)) +
-          " in binary without a dynamic linker; try removing -Wl,-" +
-          (sym->isPreemptible ? "preemptible" : "local") + "-caprelocs=elf" +
-          referencedBy());
-    return;
-  }
-  assert(ctx.hasDynsym && "Should have been checked in Driver.cpp");
   // We don't use a R_MIPS_CHERI_CAPABILITY relocation for the input but
   // instead need to use an absolute pointer size relocation to write
   // the offset addend
   if (!dynRelSec)
     dynRelSec = ctx.mainPart->relaDyn.get();
-  // in the case that -local-caprelocs=elf is passed we need to ensure that
-  // the target symbol is included in the dynamic symbol table
-  if (!ctx.mainPart->dynSymTab) {
-    error("R_CHERI_CAPABILITY relocations need a dynamic symbol table");
-    return;
-  }
-  if (!isSymIncludedInDynsym(ctx, *sym)) {
-    if (!needTrampoline) {
-      error("added a R_CHERI_CAPABILITY relocation but symbol not included "
-            "in dynamic symbol: " +
-            verboseToString(ctx, sym));
-      return;
-    }
+  if (needTrampoline && !isSymIncludedInDynsym(ctx, *sym)) {
     // Hack: Add a new global symbol with a unique name so that we can use
     // a dynamic relocation against it.
     // TODO: should it be possible to add STB_LOCAL symbols to .dynsymtab?