Apply Xcode11 changes

[liuxuan30]

Apply Xcode11 changes

automatic remove warnings detected by Xcode11

[liuxuan30]

ah crap. get multiple errors, first is rebuild the test case framework with 5.1

*** Downloading ios-snapshot-test-case.framework binary at "6.1.0"
***  Skipped installing ios-snapshot-test-case.framework binary due to the error:
	"Incompatible Swift version - framework was built with 5.0.1 (swiftlang-1001.0.82.4 clang-1001.0.46.5) and the local version is 5.1 (swiftlang-1100.0.270.13 clang-1100.0.33.7)."

[liuxuan30]

it seems iOS 13 render the image has diff more than 0.1% so it's all failing.
Need more time to take a look if this is false alert, so far I only see the black/grey color different on the same pixel from diff tool:

it's a little annoying. If we increase the tolerance rate, more tests would pass.

[liuxuan30]

another image:

this is very obvious, but still, the same issue.

[liuxuan30]

among the false alerts, I actually capture a nasty change of minimumIntegerDigits

Declaration
var minimumIntegerDigits: Int { get set }
Discussion
By default, this property is set to 0.

however for iOS 13, it's default is 1 now

(lldb) po [[[NSNumberFormatter alloc] init] minimumIntegerDigits]
1

so several UTs that has decimals such as .0 and .9 would be 0.0 and 0.9 now, causing chart shifting and diff

[liuxuan30]

I think I'm gonna just rebuild the images, and use the default formatting, since 0.9 makes more sense than .9 by default. And people used to complain why the default formatter has no prefix zero...