Solved an issue with preprocessor comment handling

Issue was with pointer passing

Author: EbinJose2002

flang/lib/Parser/prescan.cpp

@@ -564,7 +564,7 @@ bool Prescanner::MustSkipToEndOfLine() const {
     return true; // skip over ignored columns in right margin (73:80)
   } else if (*at_ == '!' && !inCharLiteral_ &&
       (!inFixedForm_ || tabInCurrentLine_ || column_ != 6)) {
-    return !IsCompilerDirectiveSentinel(at_);
+    return !IsCompilerDirectiveSentinel(at_ + 1);
   } else {
     return false;
   }

flang/test/temp_test/m.mod

@@ -0,0 +1,16 @@
+!mod$ v1 sum:17d756d2fb56521c
+module m
+contains
+subroutine func1(foo)
+real(2)::foo
+!dir$ ignore_tkr(d) foo
+end
+subroutine func3(foo)
+real(2)::foo
+!dir$ ignore_tkr(d) foo
+end
+subroutine func4(foo)
+real(2)::foo
+!dir$ ignore_tkr(d) foo
+end
+end

flang/test/temp_test/test.f90

@@ -0,0 +1,19 @@
+module m
+ contains
+
+! Directive inside macro on same line; works
+#define MACRO(X)  subroutine func1(X);    real(2) :: X;    !dir$ ignore_tkr(d) X; end subroutine func1;
+MACRO(foo)
+
+! Same subroutine, but after preprocessor expansion (-e -fno-reformat); syntax error
+  ! subroutine func2(foo);  real(2) :: foo; !dir$ ignore_tkr(d) foo;  end subroutine func2;
+
+! Parses with line wrap before !dir$
+  subroutine func3(foo);     real(2) :: foo;
+  !dir$ ignore_tkr(d) foo; end subroutine func3;
+
+! Parses with line wrap after !dir$, but swallows the directive
+  subroutine func4(foo); real(2) :: foo; !dir$ ignore_tkr(d) foo;
+  end subroutine func4;
+
+end module