t4034/cpp: actually test that operator tokens are not split

8d96e7288f (t4034: bulk verify builtin word regex sanity, 2010-12-18)
added many tests with the intent to verify that operators consisting of
more than one symbol are kept together. These are tested by probing a
transition from, e.g., a!=b to x!=y, which results in the word-diff

  [-a-]{+x+}!=[-b-]{+y+}

But that proves only that the letters and operators are separate tokens.
To prove that != is an unseparable token, we have to probe a transition
from, e.g., a=b to a!=b having a word-diff

  a[-=-]{+!=+}b

that proves that the ! is not separate from the =.

In the post-image, add to or remove from operators a character that
turns it into another valid operator.

Change the identifiers used around operators such that the diff
algorithm does not have an incentive to match, e.g., a<b in one spot
in the pre-image with a<b elsewhere in the post-image.

Adjust the expected output to match the new differences. Notice that
there are some undesirable tokenizations around e, ., and -.  This will
be addressed in a later change.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4034/cpp/post

@@ -1,19 +1,16 @@
 Foo() : x(0&42) { bar(x); }
 cout<<"Hello World?\n"<<endl;
 (1) (-1e10) (0xabcdef) 'y'
-[x] x->y x.y
-!x ~x x++ x-- x*y x&y
-x*y x/y x%y
-x+y x-y
-x<<y x>>y
-x<y x<=y x>y x>=y
-x==y x!=y
-x&y
-x^y
-x|y
-x&&y
-x||y
-x?y:z
-x=y x+=y x-=y x*=y x/=y x%=y x<<=y x>>=y x&=y x^=y x|=y
-x,y
-x::y
+[a] b->*v d.*e
+~!a !~b c+ d- e**f g&&h
+a*=b c/=d e%=f
+a++b c--d
+a<<=b c>>=d
+a<=b c<d e>=f g>h
+a!=b c=d
+a^=b c|=d e&=f
+a|b
+a?:b
+a==b c+d e-f g*h i/j k%l m<<n o>>p q&r s^t u|v
+a,b
+a:b