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

tests_lit/llvm2ice_tests/elf_container.ll

 ; Tests that we generate an ELF container with fields that make sense,
 ; cross-validating against llvm-mc.
 
 ; For the integrated ELF writer, we can't pipe the output because we need
 ; to seek backward and patch up the file headers. So, use a temporary file.
 ; RUN: %p2i -i %s --filetype=obj --args -O2 --verbose none -o %t \
+; RUN:   -allow-externally-defined-symbols \
 ; RUN:   && llvm-readobj -file-headers -sections -section-data \
 ; RUN:       -relocations -symbols %t | FileCheck %s
 
 ; RUN: %if --need=allow_dump --command %p2i -i %s --args -O2 --verbose none \
+; RUN:   -allow-externally-defined-symbols \
 ; RUN:   | %if --need=allow_dump --command llvm-mc -triple=i686-nacl \
 ; RUN:     -filetype=obj -o - \
 ; RUN:   | %if --need=allow_dump --command llvm-readobj -file-headers \
 ; RUN:     -sections -section-data -relocations -symbols - \
 ; RUN:   | %if --need=allow_dump --command FileCheck %s
 
 ; Add a run that shows relocations in code inline.
 ; RUN: %p2i -i %s --filetype=obj --args -O2 --verbose none -o %t \
+; RUN:   -allow-externally-defined-symbols \
 ; RUN:   && le32-nacl-objdump -w -d -r -Mintel %t \
 ; RUN:   | FileCheck --check-prefix=TEXT-RELOCS %s
 
 ; Use intrinsics to test external calls.
 declare void @llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i32, i1)
 declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i32, i1)
 
 ; Try other external functions (for cross tests).
 ; Not testing external global variables since the NaCl bitcode writer
 ; refuses to freeze such IR.
@@ skipping 609 matching lines @@
 ; CHECK:        Symbol {
 ; CHECK:          Name: memset
 ; CHECK-NEXT:     Value: 0x0
 ; CHECK-NEXT:     Size: 0
 ; CHECK-NEXT:     Binding: Global
 ; CHECK-NEXT:     Type: None
 ; CHECK-NEXT:     Other: 0
 ; CHECK-NEXT:     Section: Undefined
 ; CHECK-NEXT:   }
 ; CHECK: ]