Fix typos (#6775)

* s/Innteger/Integer/

* s/diretory/directory/

* s/Bufer/Buffer/

* s/defalt/default/

* s/covearge/coverage/

array.c

@@ -2086,7 +2086,7 @@ rb_ary_first(int argc, VALUE *argv, VALUE ary)
  *
  *  If +self+ is empty, returns +nil+.
  *
- *  When non-negative \Innteger argument +n+ is given,
+ *  When non-negative \Integer argument +n+ is given,
  *  returns the last +n+ elements in a new \Array:
  *
  *    a = [:foo, 'bar', 2]

ext/coverage/coverage.c

@@ -131,7 +131,7 @@ rb_coverage_setup(int argc, VALUE *argv, VALUE klass)
  * Start/resume the coverage measurement.
  *
  * Caveat: Currently, only process-global coverage measurement is supported.
- * You cannot measure per-thread covearge. If your process has multiple thread,
+ * You cannot measure per-thread coverage. If your process has multiple thread,
  * using Coverage.resume/suspend to capture code coverage executed from only
  * a limited code block, may yield misleading results.
  */
@@ -470,7 +470,7 @@ rb_coverage_running(VALUE klass)
  * This feature is experimental, so these APIs may be changed in future.
  *
  * Caveat: Currently, only process-global coverage measurement is supported.
- * You cannot measure per-thread covearge.
+ * You cannot measure per-thread coverage.
  *
  * = Usage
  *

file.c

@@ -7284,7 +7284,7 @@ const char ruby_null_device[] =
  *
  *  - ::blockdev?: Returns whether the file at the given path is a block device.
  *  - ::chardev?: Returns whether the file at the given path is a character device.
- *  - ::directory?: Returns whether the file at the given path is a diretory.
+ *  - ::directory?: Returns whether the file at the given path is a directory.
  *  - ::executable?: Returns whether the file at the given path is executable
  *    by the effective user and group of the current process.
  *  - ::executable_real?: Returns whether the file at the given path is executable

io_buffer.c

@@ -535,7 +535,7 @@ io_flags_for_size(size_t size)
  *  Create a new zero-filled IO::Buffer of +size+ bytes.
  *  By default, the buffer will be _internal_: directly allocated chunk
  *  of the memory. But if the requested +size+ is more than OS-specific
- *  IO::Bufer::PAGE_SIZE, the buffer would be allocated using the
+ *  IO::Buffer::PAGE_SIZE, the buffer would be allocated using the
  *  virtual memory mechanism (anonymous +mmap+ on Unix, +VirtualAlloc+
  *  on Windows). The behavior can be forced by passing IO::Buffer::MAPPED
  *  as a second parameter.

vm_backtrace.c

@@ -805,7 +805,7 @@ backtrace_load_data(VALUE self, VALUE str)
  *  call-seq: Thread::Backtrace::limit -> integer
  *
  *  Returns maximum backtrace length set by <tt>--backtrace-limit</tt>
- *  command-line option. The defalt is <tt>-1</tt> which means unlimited
+ *  command-line option. The default is <tt>-1</tt> which means unlimited
  *  backtraces. If the value is zero or positive, the error backtraces,
  *  produced by Exception#full_message, are abbreviated and the extra lines
  *  are replaced by <tt>... 3 levels... </tt>