Added example for integer constant [DOCS]

[xgupta]

LGTM, But also adding @aqjune as a second reviewer.

Would you please also add the example for Boolean, Float-Point, Null pointer, and Token constant so the Simple Constants section looks complete?
Feel free to ask if you can't find their examples in test cases.

[xgupta]

Also please update the title to include a tag like for this one [Docs].

[aqjune]

Hi,

Would you explain what this patch is for?

I think add %in, 1 isn't constant... it is an instruction.

[sushmaunnibhavi]

In D100710#2696919, @aqjune wrote:

Hi,

Would you explain what this patch is for?

I think add %in, 1 isn't constant... it is an instruction.

Actually, this patch is for adding examples for the simple constants section in Langref.

[aqjune]

I'm not sure whether this is a good direction - adding one example for each item might be pretty verbose considering that they are basic constructs.
What about having a code snippet that includes all of these types (including integers) after There are no constants of type x86_mmx.?

+ Adding reviewers who are working as reviewers for LangRef patches

[nikic]

Yeah, this doesn't look particularly useful to me.

Something I'd love to see though is a listing of special values for all floating point types. Always takes me a while to figure out how to test various inf/nan/sz for different float types, with their encoding peculiarities.

llvm/docs/LangRef.rst

 
 **Boolean constants**
     The two strings '``true``' and '``false``' are both valid constants
     of the ``i1`` type.
 **Integer constants**
     Standard integers (such as '4') are constants of the
     :ref:`integer <t_integer>` type. Negative numbers may be used with
     integer types.
+
+    .. code-block:: llvm
+    
+    %sum1 = add i32 %in, 1
+
 **Floating-point constants**
     Floating-point constants use standard decimal notation (e.g.
     123.421), exponential notation (e.g. 1.23421e+2), or a more precise
     hexadecimal notation (see below). The assembler requires the exact
     decimal value of a floating-point constant. For example, the
     assembler accepts 1.25 but rejects 1.3 because 1.3 is a repeating
     decimal in binary. Floating-point constants must have a
     :ref:`floating-point <t_floating>` type.