Enable vertical pixel-snapping when drawing glyph runs

 - Devices with vertical antialiasing would render text as blurry if rendered on a fractional vertical coordinate.
   - CGContext functions that draw glyphs do not necessarily use coordinates from our custom text renderer,
     which already has pixel snapping enabled.
   - As such, manually round the y-translation in CGContext::DrawGlyphRun()
 - Updated reference images for two drawing tests dealing with line height.

 Fixes microsoft#1594

Frameworks/CoreGraphics/CGContext.mm

@@ -44,6 +44,7 @@
 #include <COMIncludes_end.h>
 
 #import <atomic>
+#import <cmath>
 #import <list>
 #import <vector>
 #import <stack>
@@ -1925,6 +1926,9 @@ void CGContextSetPatternPhase(CGContextRef context, CGSize phase) {
     CGAffineTransform textTransform = CGAffineTransformScale(textMatrix, 1.0, -1.0);
     CGAffineTransform deviceTransform = CGContextGetUserSpaceToDeviceSpaceTransform(this);
 
+    // Snap the vertical baseline to the nearest pixel to avoid blurring on devices with vertical antialiasing
+    textTransform.ty = std::round(textTransform.ty);
+
     CGAffineTransform finalTextTransform = CGAffineTransformConcat(textTransform, deviceTransform);
     if ((fabs(finalTextTransform.a * glyphRun->fontEmSize) <= c_glyphThreshold &&
          fabs(finalTextTransform.b * glyphRun->fontEmSize) <= c_glyphThreshold) ||