Allow ability to name unnamed global addresses in Subzero.

tests_lit/llvm2ice_tests/unnamed.ll

+; Tests that we name unnamed global addresses.
+
+; RUN: %llvm2ice -notranslate -verbose=inst -default-global-prefix=__g %s \
+; RUN:     | FileCheck %s
+
+; RUN: %llvm2ice -notranslate -verbose=inst -default-global-prefix=h \
+; RUN:    %s 2>&1 | FileCheck --check-prefix=BAD %s
+
+@0 = internal global [4 x i8] zeroinitializer, align 4
+
+; CHECK:      @__g0 = internal global [4 x i8] zeroinitializer, align 4
+
+@1 = internal constant [10 x i8] c"Some stuff", align 1
+
+; CHECK-NEXT: @__g1 = internal constant [10 x i8] c"Some stuff", align 1
+
+
+define i32 @2(i32 %v) {
+  ret i32 %v
+}
+
+; CHECK-NEXT: define i32 @__g2(i32 %v) {
+; CHECK-NEXT: __0:
+; CHECK-NEXT:   ret i32 %v
+; CHECK-NEXT: }
+
+define void @hg() {
+  ret void
+}
+
+; BAD: Warning: Default global prefix 'h' conflicts with name 'hg'.
+
+; CHECK-NEXT: define void @hg() {
+; CHECK-NEXT: __0:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+
+define void @3() {
+  ret void
+}
+
+; CHECK-NEXT: define void @__g3() {
+; CHECK-NEXT: __0:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+