Introduce model of global initializers in Subzero.

tests_lit/llvm2ice_tests/global.ll

Index: tests_lit/llvm2ice_tests/global.ll
diff --git a/tests_lit/llvm2ice_tests/global.ll b/tests_lit/llvm2ice_tests/global.ll
index 2b1d1e29cd8cbb1fe559335d8e2705ae94d7499f..dd8d55fda3b0819fded78cced6d7e945436af384 100644
--- a/tests_lit/llvm2ice_tests/global.ll
+++ b/tests_lit/llvm2ice_tests/global.ll
@@ -5,8 +5,8 @@
 ; RUN: %lc2i -i %s --args --verbose inst | FileCheck %s

[jvoung (off chromium), 2014/10/07 15:35:31]

Does removing the external, or having this new model happen to fix lc2i? Don't
worry about it for this CL if it doesn't... I'm just checking.

[Karl, 2014/10/07 15:56:22]

The reason this test was failing to work in p2i was because of the external.
l2ci (i.e. the IceConverter) still allows external symbols. This is intentional.
It makes doing certain types of cross tool tests possible. That is, it allows us
a way to compile the same external reference using llvm2ice and llc, allowing us
to test if they behave the same way.

 ; RUN: %lc2i -i %s --args --verbose none | FileCheck --check-prefix=ERRORS %s
 
+; Note: PNaCl ABI Doesn't allow external globals. Hence, not tested.
 @intern_global = internal global [4 x i8] c"\00\00\00\0C", align 4
-@extern_global = external global [4 x i8]
 
 define i32 @test_intern_global() {
 ; CHECK: define i32 @test_intern_global
@@ -16,12 +16,4 @@ entry:
   ret i32 %v0
 }
 
-define i32 @test_extern_global() {
-; CHECK: define i32 @test_extern_global
-entry:
-  %__1 = bitcast [4 x i8]* @extern_global to i32*
-  %v0 = load i32* %__1, align 1
-  ret i32 %v0
-}
-
 ; ERRORS-NOT: ICE translation error