Revert "Default to the medium code model in x86 linux (#53391)"

This reverts commit 7536f35.

src/aotcompile.cpp

@@ -4,7 +4,6 @@
 #include "platform.h"
 
 // target support
-#include "llvm/Support/CodeGen.h"
 #include <llvm/ADT/Triple.h>
 #include <llvm/ADT/Statistic.h>
 #include <llvm/Analysis/TargetLibraryInfo.h>
@@ -1505,11 +1504,10 @@ void jl_dump_native_impl(void *native_code,
     if (TheTriple.isOSLinux() || TheTriple.isOSFreeBSD()) {
         RelocModel = Reloc::PIC_;
     }
-
     CodeModel::Model CMModel = CodeModel::Small;
-    if (TheTriple.isPPC() || (TheTriple.isX86() && TheTriple.isArch64Bit() && TheTriple.isOSLinux())) {
-        // On PPC the small model is limited to 16bit offsets. For very large images the small code model
-        CMModel = CodeModel::Medium; //  isn't good enough on x86 so use Medium, it has no cost because only the image goes in .ldata
+    if (TheTriple.isPPC()) {
+        // On PPC the small model is limited to 16bit offsets
+        CMModel = CodeModel::Medium;
     }
     std::unique_ptr<TargetMachine> SourceTM(
         jl_ExecutionEngine->getTarget().createTargetMachine(
@@ -1549,12 +1547,6 @@ void jl_dump_native_impl(void *native_code,
                                      GlobalVariable::ExternalLinkage,
                                      data, "jl_system_image_data");
         sysdata->setAlignment(Align(64));
-#if JL_LLVM_VERSION >= 180000
-        sysdata->setCodeModel(CodeModel::Large);
-#else
-        if (TheTriple.isX86() && TheTriple.isArch64Bit() && TheTriple.isOSLinux())
-            sysdata->setSection(".ldata");
-#endif
         addComdat(sysdata, TheTriple);
         Constant *len = ConstantInt::get(sysimgM.getDataLayout().getIntPtrType(Context), z->size);
         addComdat(new GlobalVariable(sysimgM, len->getType(), true,