[docs] use "=" in options with arguments

This is a fixup for llvm#141851 and consistently applies the "=" to all
options with additional arguments.

Before 14 out of 22 options with arguments used "=" and 7 didn't.

Author: kwk

llvm/docs/CommandGuide/lit.rst

@@ -112,7 +112,7 @@ OUTPUT OPTIONS
 
  Enable -v, but for all tests not just failed tests.
 
-.. option:: -o PATH, --output PATH
+.. option:: -o=PATH, --output=PATH
 
  Write test results to the provided path.
 
@@ -187,23 +187,23 @@ EXECUTION OPTIONS
 
  Don't execute any tests (assume that they pass).
 
-.. option:: --xunit-xml-output XUNIT_XML_OUTPUT
+.. option:: --xunit-xml-output=XUNIT_XML_OUTPUT
 
  Write XUnit-compatible XML test reports to the specified file.
 
 .. option:: --report-failures-only
 
  Only include failures (see :ref:`test-status-results`) in the report.
 
-.. option:: --resultdb-output RESULTDB_OUTPUT
+.. option:: --resultdb-output=RESULTDB_OUTPUT
 
  Write LuCI ResultDB compatible JSON to the specified file.
 
-.. option:: --time-trace-output TIME_TRACE_OUTPUT
+.. option:: --time-trace-output=TIME_TRACE_OUTPUT
 
  Write Chrome tracing compatible JSON to the specified file
 
-.. option:: --timeout MAXINDIVIDUALTESTTIME
+.. option:: --timeout=MAXINDIVIDUALTESTTIME
 
  Maximum time to spend running a single test (in seconds). 0 means no time
  limit. [Default: 0]
@@ -214,11 +214,11 @@ EXECUTION OPTIONS
  ``0`` means no time limit, and ``0`` is the default. Note that this is not an
  alias for :option:`--max-time`; the two are different kinds of maximums.
 
-.. option:: --max-failures MAX_FAILURES
+.. option:: --max-failures=MAX_FAILURES
 
  Stop execution after the given number of failures.
 
-.. option:: --max-retries-per-test N
+.. option:: --max-retries-per-test=N
 
  Retry running failed tests at most ``N`` times.
  Out of the following options to rerun failed tests the