[clang] [SYCL][Driver] Pass -lsycl by default for SYCL compilation. (PR #174877)

[Fangrui Song via cfe-commits]

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@@ -16,11 +16,16 @@ namespace driver {
 
 class SYCLInstallationDetector {
 public:
+  SYCLInstallationDetector(const Driver &D);
   SYCLInstallationDetector(const Driver &D, const llvm::Triple &HostTriple,
                            const llvm::opt::ArgList &Args);
 
   void addSYCLIncludeArgs(const llvm::opt::ArgList &DriverArgs,
                           llvm::opt::ArgStringList &CC1Args) const;
+
+private:
+  const Driver &D;
+  llvm::SmallVector<llvm::SmallString<128>, 4> InstallationCandidates;
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MaskRay wrote:

`sizeof(llvm::SmallVector<llvm::SmallString<128>, 4>)` is quite large. If avoiding a heap allocation isn't that important , suggest `SmallVector<0>` for the inner type.

https://github.com/llvm/llvm-project/pull/174877