Restore "MSL writer: make signed int overflow defined behaviour"

This reverts commit e33b0baa08.

Added tests/expressions/literals/intmin.wgsl test.

Bug: tint:124
Change-Id: I3d46f939ff20fa377ddb5fcb52f9afe728b8e430
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/60441
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: David Neto <dneto@google.com>

test/expressions/unary/negate/negate.wgsl

@@ -0,0 +1,7 @@
+fn i(x : i32) -> i32 {
+  return -x;
+}
+
+fn vi(x : vec4<i32>) -> vec4<i32> {
+  return -x;
+}

test/expressions/unary/negate/negate.wgsl.expected.hlsl

@@ -0,0 +1,12 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+int i(int x) {
+  return -(x);
+}
+
+int4 vi(int4 x) {
+  return -(x);
+}

test/expressions/unary/negate/negate.wgsl.expected.msl

@@ -0,0 +1,20 @@
+#include <metal_stdlib>
+
+using namespace metal;
+
+int tint_unary_minus(const int v) {
+  return select(-v, v, v == -2147483648);
+}
+
+int4 tint_unary_minus_1(const int4 v) {
+  return select(-v, v, v == -2147483648);
+}
+
+int i(int x) {
+  return tint_unary_minus(x);
+}
+
+int4 vi(int4 x) {
+  return tint_unary_minus_1(x);
+}
+

test/expressions/unary/negate/negate.wgsl.expected.spvasm

@@ -0,0 +1,36 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 17
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %i "i"
+               OpName %x "x"
+               OpName %vi "vi"
+               OpName %x_0 "x"
+       %void = OpTypeVoid
+          %1 = OpTypeFunction %void
+        %int = OpTypeInt 32 1
+          %5 = OpTypeFunction %int %int
+      %v4int = OpTypeVector %int 4
+         %11 = OpTypeFunction %v4int %v4int
+%unused_entry_point = OpFunction %void None %1
+          %4 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %i = OpFunction %int None %5
+          %x = OpFunctionParameter %int
+          %9 = OpLabel
+         %10 = OpSNegate %int %x
+               OpReturnValue %10
+               OpFunctionEnd
+         %vi = OpFunction %v4int None %11
+        %x_0 = OpFunctionParameter %v4int
+         %15 = OpLabel
+         %16 = OpSNegate %v4int %x_0
+               OpReturnValue %16
+               OpFunctionEnd

test/expressions/unary/negate/negate.wgsl.expected.wgsl

@@ -0,0 +1,7 @@
+fn i(x : i32) -> i32 {
+  return -(x);
+}
+
+fn vi(x : vec4<i32>) -> vec4<i32> {
+  return -(x);
+}