[clang] [clang][SourceManager] Use `getFileLoc` when computing `getPresumedLoc` (PR #168402)

[Aaron Ballman via cfe-commits]

================
@@ -9,9 +9,8 @@
 
 #define t(x) x
 
-t(a
-3)
-
-t(b
-__LINE__)
+t(
+  a 3)
----------------
AaronBallman wrote:

Can you help me understand why adding whitespace here will repair the test failure?

https://github.com/llvm/llvm-project/pull/168402