test: check that size argument errors are emitted at call site

Add tests for the "negative size argument in make.*" and "size argument
too large in make.*" error messages to appear at call sites in case the
size is a const defined on another line.

As suggested by Matthew in a comment on CL 69910.

Change-Id: I5c33d4bec4e3d20bb21fe8019df27999997ddff3
Reviewed-on: https://go-review.googlesource.com/100395Reviewed-by: Matthew Dempsky <mdempsky@google.com>

test/makemap.go

@@ -18,6 +18,12 @@ func main() {
 	sink = make(T, -1)            // ERROR "negative size argument in make.*"
 	sink = make(T, uint64(1<<63)) // ERROR "size argument too large in make.*"
 
+	// Test that errors are emitted at call sites, not const declarations
+	const x = -1
+	sink = make(T, x) // ERROR "negative size argument in make.*"
+	const y = uint64(1 << 63)
+	sink = make(T, y) // ERROR "size argument too large in make.*"
+
 	sink = make(T, 0.5) // ERROR "constant 0.5 truncated to integer"
 	sink = make(T, 1.0)
 	sink = make(T, float32(1.0)) // ERROR "non-integer size argument in make.*"