Bump ABI version to 7 for Swift 5 rdar://problem/44203212

Author: najacque

lib/IRGen/IRGenModule.h

@@ -461,7 +461,7 @@ enum class MangledTypeRefRole {
 class IRGenModule {
 public:
   // The ABI version of the Swift data generated by this file.
-  static const uint32_t swiftVersion = 6;
+  static const uint32_t swiftVersion = 7;
 
   IRGenerator &IRGen;
   ASTContext &Context;

test/IRGen/objc.swift

@@ -147,7 +147,7 @@ class WeakObjC {
 // CHECK:  i32 1, !"Objective-C Version", i32 2}
 // CHECK:  i32 1, !"Objective-C Image Info Version", i32 0}
 // CHECK:  i32 1, !"Objective-C Image Info Section", !"__DATA,__objc_imageinfo,regular,no_dead_strip"}
-//   67241472 == (5 << 24) | (0 << 16) | (6 << 8). 
-//     5 and 0 is the current major.minor version. 6 is the Swift ABI version.
-// CHECK:  i32 4, !"Objective-C Garbage Collection", i32 83887616}
-// CHECK:  i32 1, !"Swift Version", i32 6}
+//   83887872 == (5 << 24) | (0 << 16) | (7 << 8). 
+//     5 and 0 is the current major.minor version. 7 is the Swift ABI version.
+// CHECK:  i32 4, !"Objective-C Garbage Collection", i32 83887872}
+// CHECK:  i32 1, !"Swift Version", i32 7}