[Subzero][MIPS32] Add argument handling in LowerCall

tests_lit/llvm2ice_tests/callArgs.ll

Index: tests_lit/llvm2ice_tests/callArgs.ll
diff --git a/tests_lit/llvm2ice_tests/callArgs.ll b/tests_lit/llvm2ice_tests/callArgs.ll
new file mode 100644
index 0000000000000000000000000000000000000000..95af1f4241c150f6aadb52ab1660dfc0253a3462
--- /dev/null
+++ b/tests_lit/llvm2ice_tests/callArgs.ll
@@ -0,0 +1,51 @@
+; RUN: %if --need=target_MIPS32 --need=allow_dump \
+; RUN:   --command %p2i --filetype=asm --assemble \
+; RUN:   --disassemble --target mips32 -i %s --args -O2 --skip-unimplemented \
+; RUN:   -allow-externally-defined-symbols \
+; RUN:   | %if --need=target_MIPS32 --need=allow_dump \
+; RUN:   --command FileCheck --check-prefix MIPS32 %s
+
+
+
+declare void @voidCall5i32(i32 %a1, i32 %a2, i32 %a3, i32 %a4, i32 %a5)
+declare void @voidCall5i64(i64 %a1, i64 %a2, i64 %a3, i64 %a4, i64 %a5)
+declare void @voidCalli32i64i32(i32 %a1, i64 %a2, i32 %a3)
+
+define internal void @Call() {
+  call void @voidCall5i32(i32 1, i32 2, i32 3, i32 4, i32 5)
+  call void @voidCall5i64(i64 1, i64 2, i64 3, i64 4, i64 5)
+  call void @voidCalli32i64i32(i32 1, i64 2, i32 3)
+  ret void
+}
+; MIPS32: li    v0,5
+; MIPS32: sw	v0,16(sp)
+; MIPS32: li	a0,1
+; MIPS32: li	a1,2
+; MIPS32: li	a2,3
+; MIPS32: li	a3,4
+; MIPS32: jal
+	
+; MIPS32: li	v0,0
+; MIPS32: li	v1,3
+; MIPS32: sw	v0,20(sp)
+; MIPS32: sw	v1,16(sp)
+; MIPS32: li	v0,0
+; MIPS32: li	v1,4
+; MIPS32: sw	v0,28(sp)
+; MIPS32: sw	v1,24(sp)
+; MIPS32: li	v0,0
+; MIPS32: li	v1,5
+; MIPS32: sw	v0,36(sp)
+; MIPS32: sw	v1,32(sp)
+; MIPS32: li	a0,1
+; MIPS32: li	a1,0
+; MIPS32: li	a2,2
+; MIPS32: li	a3,0
+; MIPS32: jal
+
+; MIPS32: li	v0,3
+; MIPS32: sw	v0,16(sp)
+; MIPS32: li	a0,1
+; MIPS32: li	a2,2
+; MIPS32: li	a3,0
+; MIPS32: jal