[PATCH] [static analyzer] Emit buffer overflow warning in strcpy fucntion when uninitialized source array of known length(> dest length) is used

[Arthur O'Dwyer]

Your test cases and commit message look wrong to me.

```
char x[3] = "abc";
char y[4] = "ab";
strcpy(x,y);  // This should not warn, or at least should give a suppressible diagnostic,
              // since no overflow occurs: "ab" fits into x just fine

char x[3] = "abc";
char y[4];
strcpy(x,y);  // This should give a use-before-def diagnostic for y

char x[3] = "abc";
char y[100];
strcpy(y, x);  // This should give the "overflow" diagnostic, since it definitely attempts to strcpy an array of char that is not null-terminated
```

http://reviews.llvm.org/D6012