Remove __STDC_FORMAT_MACROS.

Our mingw doesn't use this. (It does however still use
__STDC_CONSTANT_MACROS and __STDC_LIMIT_MACROS.)

Test: treehugger
Change-Id: I415017093b9ccffd21fd41f17a2f4387839a0f53
diff --git a/cc/config/x86_windows_host.go b/cc/config/x86_windows_host.go
index 561c500..1e61b01 100644
--- a/cc/config/x86_windows_host.go
+++ b/cc/config/x86_windows_host.go
@@ -27,9 +27,8 @@
 		"-DWIN32_LEAN_AND_MEAN",
 		"-Wno-unused-parameter",
 
-		// Workaround differences in inttypes.h between host and target.
-		//See bug 12708004.
-		"-D__STDC_FORMAT_MACROS",
+		// Workaround differences in <stdint.h> between host and target.
+		// Context: http://b/12708004
 		"-D__STDC_CONSTANT_MACROS",
 
 		// Use C99-compliant printf functions (%zd).