Make sure that all globals are internal, except for "start" functions.

tests_lit/assembler/x86/immediate_encodings.ll

 ; Tests various aspects of x86 immediate encoding. Some encodings are shorter.
 ; For example, the encoding is shorter for 8-bit immediates or when using EAX.
 ; This assumes that EAX is chosen as the first free register in O2 mode.
 
 ; RUN: %p2i --filetype=obj --disassemble -i %s --args -O2 | FileCheck %s
 
 define internal i32 @testXor8Imm8(i32 %arg) {
 entry:
   %arg_i8 = trunc i32 %arg to i8
   %result_i8 = xor i8 %arg_i8, 127
@@ skipping 273 matching lines @@
   ret i64 %shl
 }
 ; CHECK-LABEL: test_via_shl64Bit
 ; CHECK: 0f a5 c2  shld edx,eax,cl
 ; CHECK: d3 e0     shl eax,cl
 ; CHECK: f6 c1 20  test cl,0x20
 
 ; Test a few register encodings of "test".
 declare i64 @llvm.ctlz.i64(i64, i1)
 
-define i64 @test_via_ctlz_64(i64 %x, i64 %y, i64 %z, i64 %w) {
+define internal i64 @test_via_ctlz_64(i64 %x, i64 %y, i64 %z, i64 %w) {
 entry:
   %r = call i64 @llvm.ctlz.i64(i64 %x, i1 false)
   %r2 = call i64 @llvm.ctlz.i64(i64 %y, i1 false)
   %r3 = call i64 @llvm.ctlz.i64(i64 %z, i1 false)
   %r4 = call i64 @llvm.ctlz.i64(i64 %w, i1 false)
   %res1 = add i64 %r, %r2
   %res2 = add i64 %r3, %r4
   %res = add i64 %res1, %res2
   ret i64 %res
 }
 ; CHECK-LABEL: test_via_ctlz_64
 ; CHECK-DAG: 85 c0 test eax,eax
 ; CHECK-DAG: 85 db test ebx,ebx
 ; CHECK-DAG: 85 f6 test esi,esi