just drop kernel code model test case

Author: kubo39

src/test/codegen/codemodels.rs

@@ -1,16 +1,13 @@
-// revisions: NOMODEL MODEL-SMALL MODEL-KERNEL MODEL-MEDIUM MODEL-LARGE
+// revisions: NOMODEL MODEL-SMALL MODEL-MEDIUM MODEL-LARGE
 //[NOMODEL] compile-flags:
 //[MODEL-SMALL] compile-flags: -C code-model=small
-//[MODEL-KERNEL] compile-flags: --target x86_64-unknown-linux-gnu -C code-model=kernel
 //[MODEL-MEDIUM] compile-flags: -C code-model=medium
 //[MODEL-LARGE] compile-flags: -C code-model=large
 
 #![crate_type = "lib"]
 
 // MODEL-SMALL: !llvm.module.flags = !{{{.*}}}
 // MODEL-SMALL: !{{[0-9]+}} = !{i32 1, !"Code Model", i32 1}
-// MODEL-KERNEL: !llvm.module.flags = !{{{.*}}}
-// MODEL-KERNEL: !{{[0-9]+}} = !{i32 1, !"Code Model", i32 2}
 // MODEL-MEDIUM: !llvm.module.flags = !{{{.*}}}
 // MODEL-MEDIUM: !{{[0-9]+}} = !{i32 1, !"Code Model", i32 3}
 // MODEL-LARGE: !llvm.module.flags = !{{{.*}}}