[compiler-rt] [test] Mark a couple files as requiring LF newlines

Since dccebdd, the majority of
files are checked out in the "native" form, which means CRLF
newlines on Windows, despite what the Git core.autocrlf setting
is set to.

Some of the profile test files fail if they have CRLF newlines;
add a .gitattributes file that forces them to be checked out
with LF newlines.

Author: mstorsjo

compiler-rt/test/profile/Inputs/.gitattributes

@@ -0,0 +1,3 @@
+instrprof-gcov-*.c text eol=lf
+instrprof-gcov-*.cpp text eol=lf
+instrprof-shared-*.c text eol=lf