[BOLT][TEST] Imported small tests

Summary:
Imported small internal tests:
- re-optimize.test
- relaxed_tailcall.test
- remove_unused.test
- retpoline_synthetic.test

(cherry picked from FBD31516680)

bolt/test/X86/Inputs/relaxed_tc.s

@@ -0,0 +1,21 @@
+  .globl main
+  .type main, %function
+main:
+	pushq	%rax
+	callq	foo
+	movl	$0x1, %eax
+	popq	%rdx
+	retq
+.size main, .-main
+
+  .globl foo
+  .type foo, %function
+foo:
+	jmp	bar
+.size foo, .-foo
+
+  .globl bar
+  .type bar, %function
+bar:
+	retq
+.size bar, .-bar

bolt/test/X86/re-optimize.test

@@ -0,0 +1,7 @@
+# Check that we detect re-optimization attempt.
+
+RUN: %clang %S/Inputs/icf-jump-tables.c -o %t.exe
+RUN: llvm-bolt %t.exe -o %t 2>&1 > /dev/null
+RUN: not llvm-bolt %t -o %t.bolt 2>&1 | FileCheck %s
+
+CHECK: BOLT-ERROR: input file was processed by BOLT. Cannot re-optimize.

bolt/test/X86/relaxed_tailcall.test

@@ -0,0 +1,7 @@
+# Check that tail calls can be 2 bytes in the output binary.
+
+RUN: %clang %cflags %S/Inputs/relaxed_tc.s -o %t.exe -Wl,-q
+RUN: llvm-bolt %t.exe -relocs -o %t
+RUN: llvm-objdump -d --disassemble-symbols=foo %t | FileCheck %s
+
+CHECK: eb 00 jmp {{.*}} <bar>

bolt/test/X86/remove_unused.test

@@ -0,0 +1,13 @@
+# Verifies that llvm-bolt is able to remove dead basic blocks. Also check that
+# the BB reordering ignores dead BBs.
+
+RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %S/Inputs/entry.s -o %t.o
+RUN: link_fdata %S/Inputs/entry.s %t.o %t.fdata
+RUN: llvm-strip --strip-unneeded %t.o
+RUN: %clang %cflags %t.o -o %t.exe -Wl,-q -nostdlib
+RUN: llvm-bolt %t.exe -data %t.fdata -o %t -funcs=_start \
+RUN:   -eliminate-unreachable -reorder-blocks=none \
+RUN:   -print-finalized -sequential-disassembly 2>&1 | FileCheck %s
+
+# Optimized
+CHECK:  BB Layout : .LBB00, .Ltmp0, .Ltmp2, .Ltmp3, .Ltmp4, .Ltmp5, .Ltmp6, .Ltmp7, .Ltmp8, .Ltmp9, .Ltmp10, .Ltmp11

bolt/test/runtime/X86/Inputs/retpoline_synthetic.cpp

@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <vector>
+
+using namespace std;
+
+class Base {
+public:
+  virtual int Foo() = 0;
+};
+
+class Derived1 : public Base {
+public:
+  int Foo() override { return 1; }
+};
+
+class Derived2 : public Base {
+public:
+  int Foo() override { return 2; }
+};
+
+class Derived3 : public Base {
+public:
+  int Foo() override { return 3; }
+};
+
+int main(int argc, char *argv[]) {
+  long long sum = 0;
+  int outerIters = atoi(argv[1]);
+  int selector = atoi(argv[2]);
+
+  Base *obj1 = new Derived1();
+  Base *obj2 = new Derived2();
+  Base *obj3 = new Derived3();
+
+  for (int j = 0; j < outerIters; j++) {
+    for (int i = 0; i < 10000; i++) {
+      switch (selector) {
+      case 1: sum += obj1->Foo();  break;
+      case 2: sum += obj2->Foo();  break;
+      case 3: sum += obj3->Foo();  break;
+      }
+    }
+  }
+  printf("%lld\n", sum);
+}

bolt/test/runtime/X86/retpoline_synthetic.test

@@ -0,0 +1,18 @@
+# Check that llvm-bolt retpoline all indirect branches and the resulting binary
+# correctly runs.
+
+REQUIRES: x86_64-linux
+
+RUN: %clangxx %S/Inputs/retpoline_synthetic.cpp -fno-jump-tables -Wl,-q,-znow \
+RUN:   -O2 -o %t.exe
+RUN: llvm-bolt %t.exe -o %t -insert-retpolines -trap-old-code &> %t.log &&\
+RUN: (echo "callq count:" ; (llvm-objdump -d %t | grep -c "callq  \*"))  &>>  %t.log ;\
+RUN: (echo "jmpq count:"  ; (llvm-objdump -d -j ".text"  %t | grep -c "jmpq   \*"))  &>> %t.log  ;\
+RUN: (echo "running binary" ; %t 1000 3  ) &>> %t.log &&  FileCheck %s -input-file %t.log
+
+CHECK:      callq count:
+CHECK-NEXT: 0
+CHECK-NEXT: jmpq count:
+CHECK-NEXT: 0
+CHECK-NEXT: running binary
+CHECK-NEXT: 30000000