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

tests_lit/llvm2ice_tests/fp.call_ret.ll

 ; This tries to be a comprehensive test of f32 and f64 call/return ops.
 ; The CHECK lines are only checking for basic instruction patterns
 ; that should be present regardless of the optimization level, so
 ; there are no special OPTM1 match lines.
 
 ; RUN: %if --need=target_X8632 --command %p2i --filetype=obj --disassemble \
-; RUN:   --target x8632 -i %s --args -O2 \
+; RUN:   --target x8632 -i %s --args -O2 -allow-externally-defined-symbols \
 ; RUN:   | %if --need=target_X8632 --command FileCheck %s
 ; RUN: %if --need=target_X8632 --command %p2i --filetype=obj --disassemble \
-; RUN:   --target x8632 -i %s --args -Om1 \
+; RUN:   --target x8632 -i %s --args -Om1 -allow-externally-defined-symbols \
 ; RUN:   | %if --need=target_X8632 --command FileCheck %s
 
 ; Can't test on ARM yet. Need to use several vpush {contiguous FP regs},
 ; instead of push {any GPR list}.
 
 define internal i32 @doubleArgs(double %a, i32 %b, double %c) {
 entry:
   ret i32 %b
 }
 ; CHECK-LABEL: doubleArgs
@@ skipping 69 matching lines @@
 }
 ; CHECK-LABEL: returnFloatConst
 ; CHECK: fld
 
 define internal double @returnDoubleConst() {
 entry:
   ret double 1.230000e+00
 }
 ; CHECK-LABEL: returnDoubleConst
 ; CHECK: fld