ARM lowering integer divide and remainder, with div by 0 checks.

runtime/szrt.c

 //===- subzero/runtime/szrt.c - Subzero runtime source ----------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements wrappers for particular bitcode instructions
@@ skipping 24 matching lines @@
 double __Sz_uitofp_i32_f64(uint32_t Value) { return (double)Value; }
 
 double __Sz_uitofp_i64_f64(uint64_t Value) { return (double)Value; }
 
 float __Sz_sitofp_i64_f32(int64_t Value) { return (float)Value; }
 
 double __Sz_sitofp_i64_f64(int64_t Value) { return (double)Value; }
 
 // Other helper calls emitted by Subzero but not implemented here:
 // Compiler-rt:
+//   __udivsi3     - udiv i32
+//   __divsi3      - sdiv i32
+//   __umodsi3     - urem i32
+//   __modsi3      - srem i32
 //   __udivdi3     - udiv i64
 //   __divdi3      - sdiv i64
 //   __umoddi3     - urem i64
 //   __moddi3      - srem i64
 //   __popcountsi2 - call @llvm.ctpop.i32
 //   __popcountdi2 - call @llvm.ctpop.i64
 // libm:
 //   fmodf - frem f32
 //   fmod  - frem f64
 // libc:
 //   setjmp  - call @llvm.nacl.setjmp
 //   longjmp - call @llvm.nacl.longjmp
 //   memcpy  - call @llvm.memcpy.p0i8.p0i8.i32
 //   memmove - call @llvm.memmove.p0i8.p0i8.i32
 //   memset  - call @llvm.memset.p0i8.i32
 // unsandboxed_irt:
 //   __nacl_read_tp