Subzero: Enable Non-SFI vector cross tests.

The driver programs for vector tests use a loop to initialize vector-type values one element at a time.  The PNaCl ABI requires the vector element index to be a constant, and the createConstantInsertExtractElementIndexPass() transformation creates an alloca instruction.  When this alloca is inside a loop, it can (and does in the cross tests) cause a stack overflow.

The workaround here is to use a noinline helper function to do the insertelement.

We didn't run into this problem until now because native and sandbox cross tests build the driver in a different way that presumably avoids running the PNaCl ABI simplification passes.

BUG= none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1560933002 .

crosstest/test_select_main.cpp

diff --git a/crosstest/test_select_main.cpp b/crosstest/test_select_main.cpp
index 1973416..d3408a0 100644
--- a/crosstest/test_select_main.cpp
+++ b/crosstest/test_select_main.cpp
@@ -25,6 +25,8 @@
 #include "test_select.h"
 }
 
+#include "insertelement.h"
+
 static const size_t MaxTestsPerFunc = 100000;
 
 template <typename T, typename TI1>
@@ -43,9 +45,9 @@
     TyI1 Cond;
     Ty Value1, Value2;
     for (size_t j = 0; j < NumElements; ++j) {
-      Cond[j] = Index() % 2;
-      Value1[j] = Values[Index() % NumValues];
-      Value2[j] = Values[Index() % NumValues];
+      setElement(Cond, j, Index() % 2);
+      setElement(Value1, j, Values[Index() % NumValues]);
+      setElement(Value2, j, Values[Index() % NumValues]);
     }
     Ty ResultLlc = select(Cond, Value1, Value2);
     Ty ResultSz = Subzero_::select(Cond, Value1, Value2);
@@ -79,9 +81,9 @@
     v4si32 Cond;
     v4f32 Value1, Value2;
     for (size_t j = 0; j < NumElements; ++j) {
-      Cond[j] = Index() % 2;
-      Value1[j] = Values[Index() % NumValues];
-      Value2[j] = Values[Index() % NumValues];
+      setElement(Cond, j, Index() % 2);
+      setElement(Value1, j, Values[Index() % NumValues]);
+      setElement(Value2, j, Values[Index() % NumValues]);
     }
     v4f32 ResultLlc = select(Cond, Value1, Value2);
     v4f32 ResultSz = Subzero_::select(Cond, Value1, Value2);
@@ -109,9 +111,9 @@
     Ty Cond;
     Ty Value1, Value2;
     for (size_t j = 0; j < NumElements; ++j) {
-      Cond[j] = Index() % 2;
-      Value1[j] = Index() % 2;
-      Value2[j] = Index() % 2;
+      setElement(Cond, j, Index() % 2);
+      setElement(Value1, j, Index() % 2);
+      setElement(Value2, j, Index() % 2);
     }
     Ty ResultLlc = select_i1(Cond, Value1, Value2);
     Ty ResultSz = Subzero_::select_i1(Cond, Value1, Value2);