Fixed some links (underscores instead of spaces)

I am not sure why this cannot be done automatically, but this change actually
fixes some links (and therefore the link checker will complain less).

doc/Type/Cool.pod

@@ -1347,7 +1347,7 @@ to L<Str|/type/Str>, and searches for C<$needle> in the string starting from C<$
 It returns the offset into the string where C<$needle> was found, and an undefined
 value if it was not found.
 
-See L<the documentation in type Str|/type/Str#routine index> for examples.
+See L<the documentation in type Str|/type/Str#routine_index> for examples.
 
 =head2 routine rindex
 
@@ -1366,7 +1366,7 @@ L<Str|/type/Str> and C<$startpos> to L<Int|/type/Int>, and
 returns the last position of C<$needle> in C<$haystack> not after C<$startpos>.
 Returns an undefined value if C<$needle> wasn't found.
 
-See L<the documentation in type Str|/type/Str#routine rindex> for examples.
+See L<the documentation in type Str|/type/Str#routine_rindex> for examples.
 
 =head2 routine roots
 

doc/Type/Metamodel/MultipleInheritance.pod

@@ -30,9 +30,9 @@ so that L<mro_unhidden|/type/Metamodel::C3MRO#method mro_unhidden> skips it.
 Adds C<$parent> as a parent type. If C<$hides> is set to a true value, the
 parent type is added as a hidden parent.
 
-C<$parent> must be a fully L<composed|/language/mop#Composition time and
-static reasoning> typed. Otherwise an exception of type
-L<X::Inheritance::NotComposed> is thrown.
+C<$parent> must be a fully
+L<composed|/language/mop#Composition_time_and_static_reasoning> typed.
+Otherwise an exception of type L<X::Inheritance::NotComposed> is thrown.
 
 =head2 method parents
 

doc/Type/Routine.pod

@@ -180,7 +180,7 @@ say double 21;      # 42
 From inside another file you'd say C<use Foo;> to load a module and import the
 exported functions.
 
-See L<Exporting and Selective Importing Modules|/language/modules#Exporting and Selective Importing>
+See L<Exporting and Selective Importing Modules|/language/modules#Exporting_and_Selective_Importing>
 for more details.
 
 =head2 trait is DEPRECATED