[ub] Fix some formatting (cplusplus#7828)

Author: jensmaurer

source/ub.tex

@@ -31,8 +31,8 @@
 };
 
 X* make_x() {
-        // The call to std::malloc can not implicitly create an object of type X
-        // because X is not an implicit-lifetime class.
+        // The call to \tcode{std::malloc} can not implicitly create an object of type \tcode{X}
+        // because \tcode{X} is not an implicit-lifetime class.
   X* p = (X*)std::malloc(sizeof(struct X));
   p->a = 1;     // undefined behavior, no set of objects give us defined behavior
   return p;
@@ -289,7 +289,7 @@
 
 \pnum
 \ubxref{basic.start.main.exit.during.destruction} \\
-If std::exit is called to
+If \tcode{std::exit} is called to
 end a program during the destruction of an object with static or thread storage duration, the program has
 undefined behavior.
 
@@ -305,7 +305,7 @@
 Exiter ex;  //
 
 int main() {}
-// Undefined behavior when destructor of static variable ex is called it will call std::exit
+// undefined behavior when destructor of static variable \tcode{ex} is called it will call \tcode{std::exit}
 \end{codeblock}
 \end{example}
 
@@ -339,8 +339,8 @@
 B b;
 
 int main() {}
-// Undefined behavior, static objects are destructed in reverse order, in this case a then b and
-// finally c. When the destructor of c is call it calls f() which passes through definition of
+// undefined behavior, static objects are destructed in reverse order, in this case \tcode{a} then \tcode{b} and
+// finally \tcode{c}. When the destructor of \tcode{c} is called, it calls \tcode{f()} which passes through the definition of
 // previously destroyed block-scope object
 \end{codeblock}
 \end{example}