[llvm-cov] Add the project summary to each source file coverage report.

This patch includes the following changes:
- Included header "Code coverage report" and include the date that the report was created.
- Included title (as specified in a command line option, (i.e llvm-cov  -project-title="Simple Test")
- In the summary, list the elf files that the source code file has contributed to.
- Used column heading for "Line No.", "Count No.", Source".

Differential Revision: https://reviews.llvm.org/D23345

llvm-svn: 279628
diff --git a/llvm/test/tools/llvm-cov/Inputs/showProjectSummary.proftext b/llvm/test/tools/llvm-cov/Inputs/showProjectSummary.proftext
new file mode 100644
index 0000000..b3cdcc7
--- /dev/null
+++ b/llvm/test/tools/llvm-cov/Inputs/showProjectSummary.proftext
@@ -0,0 +1,10 @@
+main
+# Func Hash:
+266
+# Num Counters:
+3
+# Counter Values:
+1
+20
+0
+