remove type coercion from array values to references

* Implements #3768. This is a sweeping breaking change that requires
   many (trivial) edits to Zig source code. Array values no longer
   coerced to slices; however one may use `&` to obtain a reference to
   an array value, which may then be coerced to a slice.

 * Adds `IrInstruction::dump`, for debugging purposes. It's useful to
   call to inspect the instruction when debugging Zig IR.

 * Fixes bugs with result location semantics. See the new behavior test
   cases, and compile error test cases.

 * Fixes bugs with `@typeInfo` not properly resolving const values.

 * Behavior tests are passing but std lib tests are not yet. There
   is more work to do before merging this branch.

test/compare_output.zig

@@ -465,7 +465,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\
         );
 
-        tc.setCommandLineArgs([_][]const u8{
+        tc.setCommandLineArgs(&[_][]const u8{
             "first arg",
             "'a' 'b' \\",
             "bare",
@@ -506,7 +506,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\
         );
 
-        tc.setCommandLineArgs([_][]const u8{
+        tc.setCommandLineArgs(&[_][]const u8{
             "first arg",
             "'a' 'b' \\",
             "bare",