Explicitly specify -fintegrated-as to clang/test/Driver/compilation_database.c test case.

[amyk]

Summary

It appears that this test assumes that the toolchain utilizes the integrated assembler by default,
since the expected output in the CHECKs are compilation_database.o.

However, this test fails on AIX as AIX does not utilize the integrated assembler. On AIX, the output
instead is of the form /tmp/compilation_database-*.s. Thus, this patch explicitly adds the
-fintegrated-as option to match the assumption that the integrated assembler is used by default.

[daltenty]

LGTM (without the integrated assembler there will be an assembler invocation in the compilation database that actually produces the .o instead of the clang invocation we are looking for)

clang/test/Driver/compilation_database.c

 // RUN: mkdir -p %t.workdir && cd %t.workdir
-// RUN: %clang -MD -MP --sysroot=somewhere -c -x c %s -xc++ %s -Wall -MJ - -no-canonical-prefixes 2>&1 | FileCheck %s
+// RUN: %clang -fintegrated-as -MD -MP --sysroot=somewhere -c -x c %s -xc++ %s -Wall -MJ - -no-canonical-prefixes 2>&1 | FileCheck %s
 // RUN: not %clang -c -x c %s -MJ %s/non-existant -no-canonical-prefixes 2>&1 | FileCheck --check-prefix=ERROR %s
 
-// CHECK: { "directory": "{{[^"]*}}workdir",  "file": "[[SRC:[^"]+[/|\\]compilation_database.c]]", "output": "compilation_database.o", "arguments": ["{{[^"]*}}clang{{[^"]*}}", "-xc", "[[SRC]]", "--sysroot=somewhere", "-c", "-Wall",{{.*}} "--target={{[^"]+}}"]},
-// CHECK: { "directory": "{{.*}}",  "file": "[[SRC:[^"]+[/|\\]compilation_database.c]]", "output": "compilation_database.o", "arguments": ["{{[^"]*}}clang{{[^"]*}}", "-xc++", "[[SRC]]", "--sysroot=somewhere", "-c", "-Wall",{{.*}} "--target={{[^"]+}}"]},
+// CHECK: { "directory": "{{[^"]*}}workdir",  "file": "[[SRC:[^"]+[/|\\]compilation_database.c]]", "output": "compilation_database.o", "arguments": ["{{[^"]*}}clang{{[^"]*}}", "-xc", "[[SRC]]", "-fintegrated-as", "--sysroot=somewhere", "-c", "-Wall",{{.*}} "--target={{[^"]+}}"]},
+// CHECK: { "directory": "{{.*}}",  "file": "[[SRC:[^"]+[/|\\]compilation_database.c]]", "output": "compilation_database.o", "arguments": ["{{[^"]*}}clang{{[^"]*}}", "-xc++", "[[SRC]]", "-fintegrated-as", "--sysroot=somewhere", "-c", "-Wall",{{.*}} "--target={{[^"]+}}"]},
 // ERROR: error: compilation database '{{.*}}/non-existant' could not be opened:
 
 int main(void) {
   return 0;
 }